Semi-quantitative Approaches Research Articles

Production and Functional Characterization of Murine Osteoclasts Differentiated from ER-Hoxb8-Immortalized Myeloid Progenitor Cells.

In vitro differentiation into functional osteoclasts is routinely achieved by incubation of embryonic stem cells, induced pluripotent stem cells, or primary as well as cryopreserved spleen and bone marrow-derived cells with soluble receptor activator of nuclear factor kappa-B ligand and macrophage colony-stimulating factor. Additionally, osteoclasts can be derived from co-cultures with osteoblasts or by direct administration of soluble receptor activator of nuclear factor kappa-B ligand to RAW 264.7 macrophage lineage cells. However, despite their benefits for osteoclast-associated research, these different methods have several drawbacks with respect to differentiation yields, time and animal consumption, storage life of progenitor cells or the limited potential for genetic manipulation of osteoclast precursors. In the present study, we therefore established a novel protocol for the differentiation of osteoclasts from murine ER-Hoxb8-immortalized myeloid stem cells. We isolated and immortalized bone marrow cells from wild type and genetically manipulated mouse lines, optimized protocols for osteoclast differentiation and compared these cells to osteoclasts derived from conventional sources. In vitro generated ER-Hoxb8 osteoclasts displayed typical osteoclast characteristics such as multi-nucleation, tartrate-resistant acid phosphatase staining of supernatants and cells, F-actin ring formation and bone resorption activity. Furthermore, the osteoclast differentiation time course was traced on a gene expression level. Increased expression of osteoclast-specific genes and decreased expression of stem cell marker genes during differentiation of osteoclasts from ER-Hoxb8-immortalized myeloid progenitor cells were detected by gene array and confirmed by semi-quantitative and quantitative RT-PCR approaches. In summary, we established a novel method for the quantitative production of murine bona fide osteoclasts from ER-Hoxb8 stem cells generated from wild type or genetically manipulated mouse lines. These cells represent a standardized and theoretically unlimited source for osteoclast-associated research projects.

Abstract 5118: In-vivo non-invasive mitochondrial evaluation of 3D human skin

Abstract Alterations in metabolism are considered one of the hallmarks of cancer and have been associated with changes in mitochondrial organization. The latter is typically studied in two-dimensional cell cultures, using exogenous stains, and qualitative or at best semi-quantitative approaches. We have recently developed a method that relies on the automated analysis of high resolution intrinsic NADH two-photon excited fluorescence (TPEF) images of three-dimensional specimens to assess quantitatively mitochondrial clustering levels. The purpose of this study was to assess whether this approach could be extended to the analysis of endogenous TPEF images acquired in vivo from human subjects. In-vivo depth-resolved TPEF and SHG images were acquired in vivo using a MPTflex clinical tomograph (Jenlab) at 790nm excitation. The TPEF signal was detected over 410nm-650nm, whereas SHG signal was detected in the 385nm-405nm range. In this proof of principle study a patient with a basal cell carcinoma lesion and a healthy volunteer were imaged. All in vivo measurements were conducted according to an approved institutional protocol. Image processing was performed in ImJ and Matlab. A series of analytical steps were implemented to exclude from the analysis the nuclei and interstitial space and also the collagen and melanin-associated fluorescence. After the cytoplasmic isolation, we proceeded with an automated, thresholding and digital object cloning method we have previously described. The power spectral density of the corresponding two-dimensional fourier transform of each processed image was fit to a simple inverse power law decay expression to extract a parameter indicative of the levels of mitochondrial clustering, β. Increased β in our study represents more clustered mitochondrial formations. The detailed depth-dependent analysis demonstrates distinct patterns of the clustering for the healthy and diseased tissue examined. An increase in mitochondrial clustering from the superficial to the basal layer is detected for the healthy sample, an outcome in accordance to previously results observed in fresh biopsies from healthy cervical epithelia. Since both the cervical and the skin epithelium are of similar histological type our finding is not startling but rather encouraging. The mitochondrial clustering values of the BCC lesion on the other hand, are depth-invariant, which implies an undifferentiated cellular phenotype, finding consistent with both the cancerous nature of the lesion and previously published in vitro and ex-vivo studies. In conclusion, we demonstrate that characterization of mitochondrial organization is feasible within three dimensional tissues of human subjects. This approach offers the potential to observe dynamically subtle changes in mitochondrial dynamics that occur during cancer development or in response to treatment, which would enrich our understanding of tissue metabolism and could further enhance current diagnostic approaches. Citation Format: Dimitra Pouli, Mihaela Balu, Bruce Tromberg, Irene Georgakoudi. In-vivo non-invasive mitochondrial evaluation of 3D human skin. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5118. doi:10.1158/1538-7445.AM2015-5118

RESEARCH IN STRATEGIC ENVIRONMENTAL ASSESSMENT NEEDS TO BETTER ADDRESS ANALYTICAL METHODS

One of the main gaps in current SEA research is the limited development of analytical methods to predict and assess environmental effects, which are tailored to plans, programmes and policies. The scientific literature is producing new standards and evidence-based conclusions on a number of issues that are potentially relevant for SEA, including health, land take, ecosystem fragmentation and energy needs and supply. However, research in SEA is hardly keeping the pace in terms of "translating" these findings into operational recommendations that can be applied in typical SEA contexts. As a result, the analytical content of SEA is often disappointingly low, and the assessment of impacts is still largely based on qualitative descriptions and general statements. Future research should be directed at innovating SEA methods, by promoting the use of appropriate spatially-explicit and (semi)quantitative approaches, which can be based on advances in relevant disciplines, and the increasing availability of data and technology.

Identification of desiccation tolerance transcripts potentially involved in rape (Brassica napus L.) seeds development and germination

To investigate regulatory processes and protective mechanisms leading to desiccation tolerance (DT) in seeds, cDNA amplified fragment length polymorphism (cDNA-AFLP) in conjunction with 128 primer combinations was used to detect differential gene expression in rape seeds in response to DT during seed development and germination. We obtained approximately 8000 transcript-derived fragments (TDFs), of which 394 TDFs with differential expression patterns (“sustained expression”, “up-regulated”, “couple with seed DT”, and “down-regulated”) were excised from gels and re-amplified by polymerase chain reaction (PCR). After sequencing and comparison with the National Center for Biotechnology Information database, 176 TDFs presented significant similarity with known genes that could be classified into the following categories: metabolism and energy, stress resistance and defense, storage, signal transduction, and other functional categories. Using semiquantitative reverse-transcription PCR and real-time PCR approaches, the significance of the differences was further confirmed in fresh seeds and dehydrated seeds. The genes that encode superoxide dismutase, peroxiredoxin, caleosin, oleosin S3, steroleosin, late embryogenesis abundant protein, glutathione reductase, β-glucosidase, S23 transcriptional repressor, and some heat-shock proteins could be associated with DT. The results of this study will aid in the identification of candidate genes for future experiments that seek to understand seed DT.

The need for “objective measurements” in FDG and amyloid PET neuroimaging

The process leading to the identification and validation of biomarkers for the diagnosis of early Alzheimer’s disease (early AD) has been a major focus of research interest in the past 10 years, and has been accompanied by a debate on the feasibility of implementing the research criteria in clinical practice. In the context of imaging performed using the two currently identified classes of AD biomarkers, i.e. markers of pathology and neurodegeneration, amyloid PET and 18F-FDG PET imaging are decisive tools whose crucial value is acknowledged in the recent guidelines for the early diagnosis of AD and other dementia conditions. The available recommendations draw on an extensive body of PET imaging literature, based mainly on visual methods. For the research criteria to be adopted in clinical settings, several uncertainties and gaps in knowledge must be overcome, in particular the low sensitivity and specificity provided by visual qualitative PET scan evaluation at the single-subject level. Indeed, the sensitivity and specificity of the 18F-FDG PET methods depend largely on the use of “objective methods” that result in improved accuracy for diagnosis and prognosis. Here, we review the most widely used parametric and semi-quantitative approaches to 18F-FDG PET and amyloid PET imaging, highlighting their importance in early and differential diagnosis in both research and clinical settings.

Palaeoclimate records 60–8 ka in the Austrian and Swiss Alps and their forelands

The European Alps and their forelands provide a range of different archives and climate proxies for developing climate records in the time interval 60–8 thousand years (ka) ago. We review quantitative and semi-quantitative approaches for reconstructing climatic variables in the Austrian and Swiss sector of the Alpine region within this time interval. Available quantitative to semi-quantitative climate records in this region are mainly based on fossil assemblages of biota such as chironomids, cladocerans, coleopterans, diatoms and pollen preserved in lake sediments and peat, the analysis of oxygen isotopes in speleothems and lake sediment records, the reconstruction of past variations in treeline altitude, the reconstruction of past equilibrium line altitude and extent of glaciers based on geomorphological evidence, and the interpretation of past soil formation processes, dust deposition and permafrost as apparent in loess-palaeosol sequences. Palaeoclimate reconstructions in the Alpine region are affected by dating uncertainties increasing with age, the fragmentary nature of most of the available records, which typically only incorporate a fraction of the time interval of interest, and the limited replication of records within and between regions. Furthermore, there have been few attempts to cross-validate different approaches across this time interval to confirm reconstructed patterns of climatic change by several independent lines of evidence. Based on our review we identify a number of developments that would provide major advances for palaeoclimate reconstruction for the period 60–8 ka in the Alps and their forelands. These include (1) the compilation of individual, fragmentary records to longer and continuous reconstructions, (2) replication of climate records and the development of regional reconstructions for different parts of the Alps, (3) the cross-validation of different proxy-types and approaches, and (4) the reconstruction of past variations in climate gradients across the Alps and their forelands. Furthermore, the development of downscaled climate model runs for the Alpine region 60–8 ka, and of forward modelling approaches for climate proxies would expand the opportunities for quantitative assessments of climatic conditions in Europe within this time-interval.

Giant cell arteritis: a systematic review of the qualitative and semiquantitative methods to assess vasculitis with 18F-fluorodeoxyglucose positron emission tomography.

Giant cell arteritis (GCA) is the most common vasculitis affecting medium and large vessels. It shows a close clinical association with polymyalgia rheumatica (PMR), a musculoskeletal inflammatory disorder, which is clinically characterized by girdles pain and stiffness. 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) is an effective tool for the diagnosis, grading, and follow-up of patients affected by GCA involving the aorta and its proximal branches, but the lack of a standardized method for the assessment of vascular inflammation remains a critical issue, potentially leading to misclassification. In our systematic review, including 19 original articles for a total of 442 GCA patients (with or without PMR symptoms) and 535 healthy controls, we described the different qualitative, semiquantitative and combined methods that have been proposed throughout the literature for assessing the presence and grading the severity of GCA-related vascular inflammation on 18F-FDG PET scans, focusing on the diagnostic performance and examining their respective advantages and limitations. The majority of the included studies adopted qualitative methods of PET image analysis, which are less sensitive but more specific than semiquantitative ones. Among the semiquantitative approaches, the aortic-to-blood pool uptake ratio of the aortic arch seems to be the most accurate method.

Multiple reaction monitoring for the detection of disease-related synaptic proteins.

Multiple reaction monitoring for the detection of disease-related synaptic proteins.

Mapping modern CO2 fluxes and mantle carbon content all along the mid-ocean ridge system

Quality criteria have been used to select ∼400 vesicularity measurements on zero-age mid-ocean ridge glasses from ∼600 data available in the literature published over the past ∼30 years. At face value, observations show that for a given depth of sampling, enriched basalts from slow spreading ridge segments are more vesicular than those from depleted and intermediate or fast spreading ridges. A shallower depth of eruption enhances these effects because lower hydrostatic pressure favours bubble expansion. In order to get an insight into these complex and intermingled processes, we used empirical and semi-quantitative approaches based on a limited number of inputs (segment depth D, spreading rate τ and K2O/TiO2 ratios). Both models give equivalent results and predict vesicularities within ±50%. From these calculations, we compute the equivalent CO2 concentration at the depth of eruption all along the oceanic ridge system. The total calculated CO2 fluxes are low ranging from 6.5±1.8 to 8.7±2.8×1011 mol/yr and the CO2 mantle content displays large variabilities from 66−19+27 to 78−40+82 ppm. In order to test these results, the mantle 3He fluxes have been evaluated using the calculated CO2 fluxes and a CO2/3He ratio of 2.2×109. These fluxes range from 295±82 to 395±127 mol/yr and are close to the values reported by Jean-Baptiste (1992) (267–534 mol/yr) and the most recent estimate (Bianchi et al., 2010, ∼527±102 mol/yr) using box-model of the three main ocean basins constrained by measurements of 3He and radiocarbon data. As these independent methods give similar helium fluxes at regional and global scales, it provides strong support to a low and heterogeneous mantle carbon concentration and distribution. Finally, the calculated volcanic CO2 emissions at oceanic ridges correspond to ∼30 seconds of anthropogenic emissions, at current rates.

High ALK mRNA expression has a negative prognostic significance in rhabdomyosarcoma

Background:Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase aberrantly expressed in cancer, but its clinical and functional importance remain controversial. Mutation or amplification of ALK, as well as its expression levels assessed by conventional immunohistochemistry methods, has been linked to prognosis in cancer, although with potential bias because of the semi-quantitative approaches. Herein, we measured ALK mRNA expression in rhabdomyosarcoma (RMS) and determined its clinical impact on patients' stratification and outcome.Methods:Specimens were obtained from RMS patients and cell lines, and ALK expression was analysed by quantitative RT–PCR, western blotting, IHC, and copy number analysis.Results:High ALK mRNA expression was detected in the vast majority of PAX3/7-FOXO1-positive tumours, whereas PAX3/7-FOXO1-negative RMS displayed considerably lower amounts of both mRNA and protein. Notably, ALK mRNA distinguished unfavourable PAX3/7-FOXO1-positive tumours from PAX3/7-FOXO1-negative RMS (P<0.0001), and also correlated with larger tumour size (P<0.05) and advanced clinical stage (P<0.01), independently of fusion gene status. High ALK mRNA levels were of prognostic relevance by Cox univariate regression analysis and correlated with increased risk of relapse (P=0.001) and survival (P=0.01), whereas by multivariate analysis elevated ALK mRNA expression resulted a negative prognostic marker when clinical stage was not included.Conclusion:Quantitative assessment of ALK mRNA expression helps to improve risk stratification of RMS patients and identifies tumours with adverse biological characteristics and aggressive behaviour.

Towards an optimal semiquantitative approach in giant cell arteritis: an 18F-FDG PET/CT case-control study

Giant cell arteritis (GCA) is the most common form of vasculitis in western countries. (18)F-FDG PET has been shown to be a valuable tool for the diagnosis of extracranial GCA, but results of studies are inconsistent due to a lack of standardized (18)F-FDG PET criteria. In this study, we compared different semiquantitative approaches using a controlled design to define the most efficient method. All patients with biopsy-proven GCA who had undergone an (18)F-FDG PET/CT scan in our PET unit were reviewed and matched with a control group based on age and sex. Different semiquantitative arterial (ascending and descending thoracic aorta and aortic arch) to background (liver, lung and venous blood pool) SUV ratios were blindly compared between GCA patients and matched controls. We included 11 patients with biopsy-proven GCA cases and 11 matched controls. There were no differences between the groups with regard to body weight, injected radioactivity, blood glucose level or CRP. The arterial to venous blood pool ratios discriminated the two groups better than other methods when applied to the aortic arch and the descending thoracic aorta (p<0.015). In particular, the highest aortic to highest blood pool SUVmax ratio, when applied to the aortic arch, provided optimal diagnostic performance (sensitivity 81.8 %, specificity 91 %, AUC 0.87; p<0.0001) using a cut-off value of 1.53. Among all tested (18)F-FDG PET/CT methods, the aortic to blood pool SUVmax ratio outperformed the liver and lung ratios. We suggest the use of this ratio for the assessment of aortic inflammation in GCA patients.

Development of a Comparative Risk Ranking System for Agents Posing a Bioterrorism Threat to Human or Animal Populations

Various systems for prioritizing biological agents with respect to their applicability as biological weapons are available, ranging from qualitative to (semi)quantitative approaches. This research aimed at generating a generic risk ranking system applicable to human and animal pathogenic agents based on scientific information. Criteria were evaluated and clustered to create a criteria list. Considering availability of data, a number of 28 criteria separated by content were identified that can be classified in 11 thematic areas or categories. Relevant categories contributing to probability were historical aspects, accessibility, production efforts, and possible paths for dispersion. Categories associated with impact are dealing with containment measures, availability of diagnostics, preventive and treatment measures in human and animal populations, impact on society, human and veterinary public health, and economic and ecological consequences. To allow data-based scoring, each criterion was described by at least 1 measure that allows the assignment of values. These values constitute quantities, ranges, or facts that are as explicit and precise as possible. The consideration of minimum and maximum values that can occur due to natural variations and that are often described in the literature led to the development of minimum and maximum criteria and consequently category scores. Missing or incomplete data, and uncertainty resulting therefrom, were integrated into the scheme via a cautious (but not overcautious) approach. The visualization technique that was used allows the description and illustration of uncertainty on the level of probability and impact. The developed risk ranking system was evaluated by assessing the risk originating from the bioterrorism threat of the animal pathogen bluetongue virus, the human pathogen Enterohemorrhagic Escherichia coli O157:H7, the zoonotic Bacillus anthracis, and Botulinum neurotoxin.

Exploring the potential of luminescence methods for dating Alpine rock glaciers

Rock glaciers contain valuable information about the spatial and temporal distribution of permafrost. The wide distribution of these landforms in high mountains promotes them as useful archives for the deciphering of the environmental conditions during their formation and evolution. However, age constraints are needed to unravel the palaeoclimatic context of rock glaciers, but numerical dating is difficult. Here, we present a case study assessing the potential of luminescence techniques (OSL, IRSL) to date the inner sand-rich layer of active rock glaciers. We focus on the signal properties and the resetting of the signal prior to deposition by investigating single grains. While most quartz shows low signal intensities and problematic luminescence characteristics, K-feldspar exhibits much brighter and well-performing signals. Most signals from plagioclases do not show suitable properties. Luminescence signals far below saturation indicate distinct but differential bleaching. The finite mixture model was used to determine the prominent populations in the equivalent dose distributions. The luminescence ages represent travel times of grains since incorporation into the rock glacier and hence, minimum ages of rock glacier formation. Luminescence ages between 3 ka and 8 ka for three rock glaciers from the Upper Engadine and Albula region (Swiss Alps) agree well with independent age estimates from relative and semi-quantitative approaches. Therefore, luminescence seems to have the potential of revealing age constraints about processes related to the formation of rock glaciers, but further investigations are required for solving some of the problems remaining and reducing the dating uncertainties.

Monitoring and quantifying dynamic physiological processes in live neurons using fluorescence recovery after photobleaching

The direct visualization of subcellular dynamic processes is often hampered by limitations in the resolving power achievable with conventional microscopy techniques. Fluorescence recovery after photobleaching has emerged as a highly informative approach to address this challenge, permitting the quantitative measurement of the movement of small organelles and proteins in living functioning cells, and offering detailed insights into fundamental cellular phenomena of physiological importance. In recent years, its implementation has benefited from the increasing availability of confocal microscopy systems and of powerful labeling techniques based on genetically encoded fluorescent proteins or other chemical markers. In this review, we present fluorescence recovery after photobleaching and related techniques in the context of contemporary neurobiological research and discuss quantitative and semi-quantitative approaches to their interpretation.

Environmental factors associated with invasion: modelling occurrence data from a coordinated sampling programme for Pacific oysters

Documenting establishment and spread of invasive species requires extensive co-ordinated sampling programmes. Identifying the factors promoting or inhibiting local establishment of an invasive species can improve capacity to predict further spread and underpin strategies to limit spread. Here, a structured sampling programme was used to assess the current distribution of feral populations of Pacific oysters, Crassostrea gigas, in Ireland. Sixty-nine sites were sampled using a standardised protocol combining semi-quantitative and quantitative approaches. Sites were chosen to represent variation in proximity to aquaculture and a range of environmental variables. Oyster populations were found at 18 locations, with densities ranging from single individuals to nine individuals per m2. The broad size range of oysters found is indicative of more than one recruitment event. Logistic regression indicated that feral oysters were positively associated with the presence of hard substrata or biogenic reef, long residence times of embayments and large intertidal areas. There was also a tendency for oysters to occur disproportionately in bays with aquaculture, but >500 m from it. Small-scale analysis within sites showed that oysters were almost exclusively attached to hard substrata and mussel shell. The approach taken here provides a rigorous repeatable methodology for future monitoring and a detailed basis for the prediction of further spread.

Quantitative approach to glucocorticosteroids analysis in human urine using LC-MS/MS

Glucocorticosteroids are included in the World Anti-Doping Agency (WADA) prohibited list as non-threshold analytes. Nevertheless, at least semi-quantitative approaches are necessary before reporting an adverse analytical finding for this class of substances. The liquid chromatography coupled to mass spectrometry (LC-MS) has been used with excellent selectivity and specificity in xenobiotic analysis in complex matrices. Real samples containing exogenous glucocorticosteroids from different administration routes were analyzed using the method proposed. Samples from systemic administration (oral route) presented levels of prednisolone or prednisone higher than 30 ng mL-1, the minimum requirement performance level used as diagnostic parameter. On the other hand, non-systemic routes seem to not have bioavailability to generate an adverse case in doping control analysis. Considering the low number of similar studies available in the literature, more urinary studies could be done using the method reported aiming to provide more information about the excretion profile of glucocorticosteroids administered by systemic and non-systemic routes.

The age of the LGM in the Western and Northwestern Alps (Switzerland and France).Results from various dating techniques

The European Alps and their forelands provide a range of different archives and climate proxies for developing climate records in the time interval 60–8 thousand years (ka) ago. We review quantitative and semi-quantitative approaches for reconstructing climatic variables in the Austrian and Swiss sector of the Alpine region within this time interval. Available quantitative to semi-quantitative climate records in this region are mainly based on fossil assemblages of biota such as chironomids, cladocerans, coleopterans, diatoms and pollen preserved in lake sediments and peat, the analysis of oxygen isotopes in speleothems and lake sediment records, the reconstruction of past variations in treeline altitude, the reconstruction of past equilibrium line altitude and extent of glaciers based on geomorphological evidence, and the interpretation of past soil formation processes, dust deposition and permafrost as apparent in loess-palaeosol sequences. Palaeoclimate reconstructions in the Alpine region are affected by dating uncertainties increasing with age, the fragmentary nature of most of the available records, which typically only incorporate a fraction of the time interval of interest, and the limited replication of records within and between regions. Furthermore, there have been few attempts to cross-validate different approaches across this time interval to confirm reconstructed patterns of climatic change by several independent lines of evidence. Based on our review we identify a number of developments that would provide major advances for palaeoclimate reconstruction for the period 60–8 ka in the Alps and their forelands. These include (1) the compilation of individual, fragmentary records to longer and continuous reconstructions, (2) replication of climate records and the development of regional reconstructions for different parts of the Alps, (3) the cross-validation of different proxy-types and approaches, and (4) the reconstruction of past variations in climate gradients across the Alps and their forelands. Furthermore, the development of downscaled climate model runs for the Alpine region 60–8 ka, and of forward modelling approaches for climate proxies would expand the opportunities for quantitative assessments of climatic conditions in Europe within this time-interval.

Development of histopathological indices in a commercial marine bivalve (Ruditapes decussatus) to determine environmental quality

Bivalve histopathology is an acknowledged tool in environmental toxicology studies, however geographically restricted, limited to a few species and still lacking the degree of detail needed to develop effective (semi)quantitative approaches. A first-time detailed histopathological screening was performed on grooved carpet shell clams collected from commercial shellfish beds in distinct coastal ecosystems of the Southern Portuguese coast: two parted sites within an impacted estuary (S1 and S2), an inlet channel of a fish farm at a considered pristine estuary (site M) and a site allocated in a clean coastal lagoon (A). A total of thirty histopathological lesions and alterations were analysed in the gills and digestive glands following a weighted condition indices approach, including inflammation-related responses, necrosis, neoplastic diseases and parasites. Digestive glands were consistently more damaged than gills, except for animals collected from site M, where the most severe lesions were found in both organs, immediately followed by S2. Clams from sites S1 and A were overall the least damaged. Neoplastic diseases were infrequent in all cases. Inflammation-related traits were some of the most common alterations progressing in animals enduring severe lesions such as digestive tubule (diverticula) and intertubular tissue necrosis. Some alterations, such as lipofuscin aggregates within digestive tubule cells, did not relate to histological lesions. Granulocytomas only occurred in heavily infected tissues. Animals from M and A presented the highest infections in the digestive gland, especially by protozoa. Gill infections were more similar between sites. Still, the level of infection does not account for all histopathological lesions in either organ. Overall, the results are in accordance with environmental parameters, such as distance to pollution sources, sediment type and hydrodynamics, and show that the combination of multiple histopathological features in these clams provides good sensitivity for inter-site distinction even when low or moderate anthropogenic impacts are at stake.

Étude rétrospective des conséquences de l’administration d’une préparation de FDG contenant de 5 % à 10 % de fluorure (18F) libre sur l’imagerie TEP/TDM de l’os sain et des foyers osseux pathologiques. Comparaison avec un groupe apparié de patients ayant reçu une préparation de FDG contenant moins de 5 % de fluorure (18F) libre

Following administration in January 2010 of a commercial preparation of FDG containing between 5 and 10% of fluoride (18F), our aim was to evaluate by means of a retrospective study the consequences of this content of free 18F on the visual and semi-quantitative approaches of the skeletal uptake on PET/CT. MethodsTwo groups of 30 patients (princeps and control) were matched for pathology, age, sex and glycaemia. The group “princeps” received the FDG preparation containing more than 5% of fluoride (18F). All examinations were done according to the standard protocol of FDG PET/CT. The SUVmax was determined in six regions of interest (ROI) in visually normal bone. For pathologic foci, we calculated a ratio of SUVmax between the focus and healthy bone (T/NTR). ResultsThe analysis of normal bone showed, for the spine, a significant difference in SUVmax between the two groups and a significant correlation with the time elapsed between FDG preparation and injection. Concerning the pathologic foci, the T/NTR of two groups were significantly different (P=0.04). ConclusionWe observed a slight increase of the SUVmax in the healthy spine of patients who received more than 5% of fluoride (18F), explained in part by a longer delay before imaging. The pathologic foci showed a T/NTR lower in the group princeps, however metastases were detected in both groups. Thus, a preparation of FDG close to the end of its shelf life can be used without real consequences for the quality of images for a given patient; in contrast, an accurate quantification of the FDG uptake in the spine requires a minimal proportion of fluoride (18F).

A real time PCR based approach for the quantitative detection of FUS-CHOP fusion transcripts in human liposarcoma

Histology still forms the backbone for the diagnosis of the myxoid and round cell subtypes of liposarcoma but the molecular identification of the different transcript variants remains a challenge, due, in part, to the complexity of multiple overlapping exons that they share between them. This study was conducted to develop and evaluate a more sensitive platform than existing semi-quantitative approaches for detecting FUS-CHOP transcripts. In the present investigation we describe a novel approach using real-time PCR to identify and differentiate the fusion transcripts formed in the t(12; 16)(q13; p11) chromosomal translocation. This method is founded on the basis of transcript individualized primers and probes, which were designed to detect specifically the different variants in both frozen and FFPE tissues. Our results show that the method is highly specific, sensitive, and superior to the widely used nested PCR approach, and is accurately able to differentiate the most common variants, as well as quantify copy numbers. Primer amplification and probe detection of FUS-CHOP from genomic DNA of human, mouse, cocker spaniel and chicken sources all resulted in completely negative results indicating this technique is specific for human RNA derived transcripts. This new method offers an additional tool in the investigation of liposarcoma that may impact considerably on missed diagnosis and it's accompanying clinical ramifications.