PET and SPECT Imaging of the Brain: History, Technical Considerations, Applications, and Radiotracers

Advances in nuclear medicine have revolutionized our ability to accurately diagnose patients with a wide array of neurologic pathologies and provide appropriate therapy. The development of new radiopharmaceuticals has made possible the identification of regional differences in brain tissue composition and metabolism. In addition, the evolution of 3-dimensional molecular imaging followed by fusion with computed tomography and magnetic resonance imaging have allowed for more precise localization of pathologies. This review will introduce single photon emission computed tomography and positron emission tomographic imaging of the brain, including the history of their development, technical considerations, and a brief overview of pertinent radiopharmaceuticals and their applications

Osteomacs interact with megakaryocytes and osteoblasts to regulate murine hematopoietic stem cell function

Networking between hematopoietic stem cells (HSCs) and cells of the hematopoietic niche is critical for stem cell function and maintenance of the stem cell pool. We characterized calvariae-resident osteomacs (OMs) and their interaction with megakaryocytes to sustain HSC function and identified distinguishing properties between OMs and bone marrow (BM)–derived macrophages. OMs, identified as CD45+F4/80+ cells, were easily detectable (3%-5%) in neonatal calvarial cells. Coculture of neonatal calvarial cells with megakaryocytes for 7 days increased OM three- to sixfold, demonstrating that megakaryocytes regulate OM proliferation. OMs were required for the hematopoiesis-enhancing activity of osteoblasts, and this activity was augmented by megakaryocytes. Serial transplantation demonstrated that HSC repopulating potential was best maintained by in vitro cultures containing osteoblasts, OMs, and megakaryocytes. With or without megakaryocytes, BM-derived macrophages were unable to functionally substitute for neonatal calvarial cell–associated OMs. In addition, OMs differentiated into multinucleated, tartrate resistant acid phosphatase–positive osteoclasts capable of bone resorption. Nine-color flow cytometric analysis revealed that although BM-derived macrophages and OMs share many cell surface phenotypic similarities (CD45, F4/80, CD68, CD11b, Mac2, and Gr-1), only a subgroup of OMs coexpressed M-CSFR and CD166, thus providing a unique profile for OMs. CD169 was expressed by both OMs and BM-derived macrophages and therefore was not a distinguishing marker between these 2 cell types. These results demonstrate that OMs support HSC function and illustrate that megakaryocytes significantly augment the synergistic activity of osteoblasts and OMs. Furthermore, this report establishes for the first time that the crosstalk between OMs, osteoblasts, and megakaryocytes is a novel network supporting HSC function

Advanced imaging techniques for neuro-oncologic tumor diagnosis, with an emphasis on PET-MRI imaging of malignant brain tumors

Purpose of review: This review will explore the latest in advanced imaging techniques, with a focus on the complementary nature of multiparametric, multimodality imaging using magnetic resonance imaging (MRI) and positron emission tomography (PET). Recent findings: Advanced MRI techniques including perfusion-weighted imaging (PWI), MR spectroscopy (MRS), diffusion-weighted imaging (DWI), and MR chemical exchange saturation transfer (CEST) offer significant advantages over conventional MR imaging when evaluating tumor extent, predicting grade, and assessing treatment response. PET performed in addition to advanced MRI provides complementary information regarding tumor metabolic properties, particularly when performed simultaneously. 18F-fluoroethyltyrosine (FET) PET improves the specificity of tumor diagnosis and evaluation of post-treatment changes. Incorporation of radiogenomics and machine learning methods further improve advanced imaging. The complementary nature of combining advanced imaging techniques across modalities for brain tumor imaging and incorporating technologies such as radiogenomics has the potential to reshape the landscape in neuro-oncology. Keywords: Advanced MRI; Amino acid PET; Brain tumor; Chemical exchange saturation transfer; Diffusion-weighted imaging; FET; Glioblastoma; Glioma; High-grade malignancy; Hybrid PET/MRI; MR spectroscopy; Metastasis; Perfusion-weighted imaging; Progression; Pseudoprogression; Pseudoresponse; Radiation necrosis; Radiogenomics; Radiomics; Treatment-related change; Tumor grading

Sendai five years on: reflections on the role of international law in the creation and reduction of disaster risk

This article offers a critical examination of the position of the Sendai Framework for Disaster Risk Reduction 2015-2030 within international law. It is argued that any interrogation into the role of international law must begin not with existing disaster risk reduction (DRR) laws and policies, but rather with an enquiry into the nature of disaster risk and the role of international law in its creation and reduction. It is demonstrated how, while areas such as international human rights law can be utilized to enforce obligations in support of DRR, other areas – in particular international investment law – actively work to undermine DRR efforts. In order for international law to be a productive tool in the reduction of disaster risk international lawyers must engage with critical work in disaster studies in order to explore the role that the former has played – and can play – in creating and addressing hazards, vulnerabilities and capacities

Intentional injury reported by young people in the Federated States of Micronesia, Kingdom of Tonga and Vanuatu

<p>Abstract</p> <p>Background</p> <p>Intentional injury presents a threat to the physical and psychological well being of young people, especially in developing countries, which carry the greatest part of the global injury burden. While the importance of this problem is recognized, there are limited population data in low and middle income countries that can guide public health action. The present study investigates the prevalence and distribution of intentional injury among young people in three Pacific Island societies, and examines behavioural and psychosocial factors related to risk of intentional injury.</p> <p>Methods</p> <p>Population surveys were conducted with <b>s</b>tudents aged 11–17 years in Pohnpei State in the Federated States of Micronesia (n = 1495), the Kingdom of Tonga (n = 2808) and Vanuatu (n = 4474). Surveys measured self-reported injury and intentional injury, sources of intentional injury, and the range of behavioural, psychological, educational and social variables that may be related to injury risk.</p> <p>Results</p> <p>Among boys and girls aged 14–17 years the respective period prevalence of intentional injury was 62% and 56% in Pohnpei, 58% and 41% in Tonga, and 33% and 24% in Vanuatu. The prevalence of intentional injury declined with age in Tonga and Vanuatu, but there was little evidence of an age-trend in Pohnpei. Across the three societies, the major sources of intentional injury among boys were 'other persons' followed by boyfriends/girlfriends and fathers. Mothers, boyfriends/girlfriends and other persons were primary sources of injury among girls. An intentional injury was reported more often by those who had been bullied (OR 1.40–1.66, P < 0.05), by regular smokers in Tonga and Vanuatu (OR 1.52–2.21, P < 0.05), and illicit drug users in Pohnpei and Vanuatu (OR 1.87–1.92, P < 0.05).</p> <p>Conclusion</p> <p>Intentional injury was reported extensively in these three populations. Interventions directed towards the school environment and which take into account the role of bullying and drug use need to be considered.</p

Studies on genes coding the firmness of strawberry (Fragaria x ananassa) fruits

Metabolizm komponentów polisacharydowych ściany komórkowej wpływa na wiele cech fenotypowych i fizjologicznych roślin, m.in. na zmiany jędrności owoców podczas ich dojrzewania. Celem badań podjętych w 2001 roku w Zakładzie Hodowli Instytutu Sadownictwa i Kwiaciarstwa było określenie, który z genów regulujących gospodarkę celulozowo-pektynową warunkuje równocześnie jędrność owoców jako cechę typową dla każdej z odmian truskawki. Badania prowadzono na genomowym DNA i cDNA truskawki 'Dukat' oraz czterech innych odmian różniących się jędrnością owoców ('Kama', 'Kent', 'Vikat', 'Salut'). W zoptymalizowanych warunkach PCR w reakcji ze starterami celU1.2/L1.2 i expUl/Ll-3 (konstrukcja na podstawie biblioteki cDNA truskawki) uzyskano produkty o długości około 3 kb i 1,2 kb (matryca: genomowe DNA) oraz 1,5 kb i 800 pz (matryca: cDNA). Wyniki sekwencjonowania produktów PCR potwierdziły, iż wyizolowane fragmenty zawierały geny celulazy i ekspansyny (86-99% homologii z sekwencjami genów podanych w Banku Genów dla roślin innych gatunków/odmian). Prace nad porównaniem sekwencji produktów PCR uzyskanych dla pozostałych analizowanych odmian są kontynuowane.Metabolism of polysaccharides in cell wall influences many phenotypic and physiological plant traits, e.g. the changes in fruit firmness during ripening. The aim of studies carried out in the Fruit Breeding Department was searching for genes responsible for cellulose - pectin transformations simultaneously regulating strawberry fruit firmness typical for each cultivar. Genomic DNA and cDNA of 'Dukat' strawberry and four other cultivars of different firmness level ('Kama', 'Kent', Vikať, 'Salut') were used as a template for PCR with primers constructed on the basis of strawberry cDNA library. Under optimised PCR conditions the products of length about of 3 kb and 1.2 kb (genomic DNA) and 1.5 kb and 800 bp (cDNA) were obtained respectively in reactions with primers celU1.2/L1.2 and expUl/Ll-3. Results of PCR product sequencing confirmed that isolated DNA fragments contained cellulase and expansin genes (86-99% homology with published in Genebank sequences of other species/cultivars). Comparable studies on PCR product sequences obtained for the other genotypes are continued

Evaluation of genetic diversification of gooseberry (R. grossularia) genotypes using RAPD and ISSR techniques

Celem pracy była ocena przydatności technik RAPD i ISSR do określenia stopnia powinowactwa genetycznego 12 odmian agrestu (R. grossularia), używanych w programach hodowlanych w Zakładzie Hodowli Roślin Sadowniczych. W oparciu o wyniki reakcji amplifikacji przeprowadzonej przy użyciu techniki RAPD i ISSR dokonano wyboru starterów, w reakcji z którymi obserwowano produkty polimorficzne, różnicujące genotypy. Analiza pokrewieństwa genotypów, oszacowanego na podstawie komputerowej analizy produktów polimorficznych wykazała, że stosowanie obu technik pozwala na pełniejszą analizę testowanych genotypów.The aim of the studies was an estimation of RAPD and ISSR techniques usefulness to determine genetic relationships of 12 gooseberry cultivars used in breeding programme at the Fruit Breeding Department. Polymorphic PCR products generated in RAPD and ISSR reaction were chosen to genetic relationship determination (Dnastar, Phylip) analysis. The results showed similar tendency for data obtained at RAPD and ISSR but simultaneous use of both techniques allowed to increase the precision in determination of relationships