275 research outputs found
First experiences with Lu-177-PSMA-617 therapy for recurrent or metastatic salivary gland cancer
BACKGROUND: Advanced salivary gland cancers become difficult to treat when they are technically irresectable and radiotherapy limits are exceeded. There is also an unmet need to improve palliative systemic therapy. Salivary glands depict the Prostate-Specific Membrane Antigen (PSMA) on (68)Ga-PSMA-PET/CT, a transmembrane protein that is targeted for diagnosis and treatment of advanced prostate cancer. Some salivary gland carcinomas also express PSMA. METHODS: This study aimed to retrospectively evaluate the effectiveness of (177)Lu-PSMA-617 therapy for recurrent or metastatic salivary gland cancers, as a last resort treatment. Patients with serious tumour-related discomfort for whom no regular option was available were selected and critically re-assessed by the tumour board. Radionuclide therapy eligibility was confirmed when tumour targeting was greater than liver SUVmax on (68)Ga-PSMA-PET/CT. The protocol aimed at four cycles of 6.0â7.4Â GBq (177)Lu-PSMA-617 every 6â8Â weeks. Clinical response was evaluated by questionnaires and radiological response by (68)Ga-PSMA-PET/CT. RESULTS: Six patients were treated with (177)Lu-PSMA: four adenoid cystic carcinomas, one adenocarcinoma NOS and one acinic cell carcinoma. In two patients, radiological response was observed, showing either stable disease or a partial response, and four patients reported immediate relief of tumour-related symptoms. Most reported side effects were grade 1â2 fatigue, nausea, bone pain and xerostomia. Four patients prematurely discontinued therapy: three due to disease progression and one due to demotivating (grade 1) side-effects. CONCLUSIONS: Palliative (177)Lu-PSMA therapy for salivary gland cancer may lead to rapid relief of tumour-associated discomfort and may even induce disease stabilization. It is safe, relatively well tolerated and can be considered when regular treatment options fail
The Added Value of [18F]FDG PET/CT in the Management of Invasive Fungal Infections
Anatomy-based imaging methods are the usual imaging methods used in assessing invasive fungal infections (IFIs). [18F]FDG PET/CT has also been used in the evaluation of IFIs. We assessed the added value of [18F]FDG PET/CT when added to the most frequently used anatomy-based studies in the evaluation of IFIs. The study was conducted in two University Medical Centers in the Netherlands. Reports of [18F]FDG PET/CT and anatomy-based imaging performed within two weeks of the [18F]FDG PET/CT scan were retrieved, and the presence and sites of IFI lesions were documented for each procedure. We included 155 [18F]FDG PET/CT scans performed in 73 patients. A total of 216 anatomy-based studies including 80 chest X-rays, 89 computed tomography studies, 14 magnetic resonance imaging studies, and 33 ultrasound imaging studies were studied. The anatomy-based studies were concordant with the [18F]FDG PET/CT for 94.4% of the scans performed. [18F]FDG PET/CT detected IFI lesions outside of the areas imaged by the anatomy-based studies in 48.6% of the scans. In 74% of the patients, [18F]FDG PET/CT added value in the management of the IFIs
Ab initio calculations of the physical properties of transition metal carbides and nitrides and possible routes to high-Tc
Ab initio linear-response calculations are reported of the phonon spectra and
the electron-phonon interaction for several transition metal carbides and
nitrides in a NaCl-type structure. For NbC, the kinetic, optical, and
superconducting properties are calculated in detail at various pressures and
the normal-pressure results are found to well agree with the experiment.
Factors accounting for the relatively low critical temperatures Tc in
transition metal compounds with light elements are considered and the possible
ways of increasing Tc are discussed.Comment: 19 pages, 7 figure
The tubarial salivary glands:A potential new organ at risk for radiotherapy
Introduction: The presence of previously unnoticed bilateral macroscopic salivary gland locations in the human nasopharynx was suspected after visualization by positron emission tomography/computed tomography with prostate-specific membrane antigen ligands (PSMA PET/CT). We aimed to elucidate the characteristics of this unknown entity and its potential clinical implications for radiotherapy. Materials and methods: The presence and configuration of the PSMA-positive area was evaluated in a retrospective cohort of consecutively scanned patients with prostate or urethral gland cancer (n = 100). Morphological and histological characteristics were assessed in a human cadaver study (n = 2). The effect of radiotherapy (RT) on salivation and swallowing was retrospectively investigated using prospectively collected clinical data from a cohort of head-neck cancer patients (n = 723). With multivariable logistic regression analysis, the association between radiotherapy (RT) dose and xerostomia or dysphagia was evaluated. Results: All 100 patients demonstrated a demarcated bilateral PSMA-positive area (average length 4 cm). Histology and 3D reconstruction confirmed the presence of PSMA-expressing, predominantly mucous glands with multiple draining ducts, predominantly near the torus tubarius. In the head-neck cancer patients, the mean RT dose to the gland area was significantly associated with physician-rated posttreatment xerostomia and dysphagia >= grade 2 at 12 months (0.019/gy, 95%CI 0.005-0.033, p =.007; 0.016/gy, 95%CI 0.001-0.031, p =.036). Follow-up at 24 months had similar results. Conclusion: The human body contains a pair of previously overlooked and clinically relevant macroscopic salivary gland locations, for which we propose the name tubarial glands. Sparing these glands in patients receiving RT may provide an opportunity to improve their quality of life. (C) 2020 The Authors. Published by Elsevier B.V
Quantification of the novel N-methyl-D-aspartate receptor ligand [11C]GMOM in man
[11C]GMOM (carbon-11 labeled N-(2-chloro-5-thiomethylphenyl)-N0-(3-[11C]methoxy-phenyl)-N0-methylguanidine) is a PET ligand that binds to the N-methyl-D-aspartate receptor with high specificity and affinity. The purpose of this first in human study was to evaluate kinetics of [11C]GMOM in the healthy human brain and to identify the optimal pharmacokinetic model for quantifying these kinetics, both before and after a pharmacological dose of S-ketamine. Dynamic 90 min [11C]GMOM PET scans were obtained from 10 subjects. In six of the 10 subjects, a second PET scan was performed following an S-ketamine challenge. Metabolite corrected plasma input functions were obtained for all scans. Regional time activity curves were fitted to various single- and two-tissue compartment models. Best fits were obtained using a two-tissue irreversible model with blood volume parameter. The highest net influx rate (Ki) of [11C]GMOM was observed in regions with high N-methyl-D-aspartate receptor density, such as hippocampus and thalamus.
A significant reduction in the Ki was observed for the entire brain after administration of ketamine, suggesting specific binding to the N-methyl-D-aspartate receptors. This initial study suggests that the [11C]GMOM could be used for quantification of N-methyl-D-aspartate receptors
Longitudinal characteristics of T2-FLAIR mismatch in IDH-mutant astrocytomas: Relation to grade, histopathology, and overall survival in the GLASS-NL cohort.
BACKGROUND: The T2-FLAIR mismatch sign is defined by signal loss of the T2-weighted hyperintense area with Fluid-Attenuated Inversion Recovery (FLAIR) on magnetic resonance imaging, causing a hypointense region on FLAIR. It is a highly specific diagnostic marker for IDH-mutant astrocytoma and is postulated to be caused by intercellular microcystic change in the tumor tissue. However, not all IDH-mutant astrocytomas show this mismatch sign and some show the phenomenon in only part of the lesion. The aim of the study is to determine whether the T2-FLAIR mismatch phenomenon has any prognostic value beyond initial noninvasive molecular diagnosis.
METHODS: Patients initially diagnosed with histologically lower-grade (2 or 3) IDH-mutant astrocytoma and with at least 2 surgical resections were included in the GLASS-NL cohort. T2-FLAIR mismatch was determined, and the growth pattern of the recurrent tumor immediately before the second resection was annotated as invasive or expansive. The relation between the T2-FLAIR mismatch sign and tumor grade, microcystic change, overall survival (OS), and other clinical parameters was investigated both at first and second resection.
RESULTS: The T2-FLAIR mismatch sign was significantly related to Grade 2 (80% vs 51%), longer post-resection median OS (8.3 vs 5.2 years), expansive growth, and lower age at second resection. At first resection, no relation was found between the mismatch sign and OS. Microcystic change was associated with areas of T2-FLAIR mismatch.
CONCLUSIONS: T2-FLAIR mismatch in IDH-mutant astrocytomas is correlated with microcystic change in the tumor tissue, favorable prognosis, and Grade 2 tumors at the time of second resection
Acting Intuition into Sense: How Film Crews Make Sense with Embodied Ways of Knowing
This study contributes to a holistic understanding of sensemaking by going beyond the mindâbody dualism. To do so, we focus analytically on a phenomenon that operates at the nexus of mind and body: intuition. By observing four film crews, we unpack how people act their intuition into sense â that is, how they transform, through action, an initial sense (intuition) that is tacit, intimate, and complex into one that is publicly displayed, simpler, and ordered (i.e., a developed sense). Our model identifies two sensemaking trajectories, each of which involves several bodily actions (e.g., displaying feelings, working hands-on, speaking assertively). These actions enable intuition to express a facet of itself and acquire new properties. This study makes three important contributions. First, it develops the holistic-relational character of sensemaking by locating it in the relations among multiple loci (cognition, language, body, and materiality) rather than in each one disjunctively. Second, it theorizes embodied sensemaking as a transformative process entailing a rich repertoire of bodily actions. Third, it extends sensemaking research by attending to the physicality and materiality of language in embodied sensemaking
A hybrid BAC physical map of potato: a framework for sequencing a heterozygous genome
<p>Abstract</p> <p>Background</p> <p>Potato is the world's third most important food crop, yet cultivar improvement and genomic research in general remain difficult because of the heterozygous and tetraploid nature of its genome. The development of physical map resources that can facilitate genomic analyses in potato has so far been very limited. Here we present the methods of construction and the general statistics of the first two genome-wide BAC physical maps of potato, which were made from the heterozygous diploid clone RH89-039-16 (RH).</p> <p>Results</p> <p>First, a gel electrophoresis-based physical map was made by AFLP fingerprinting of 64478 BAC clones, which were aligned into 4150 contigs with an estimated total length of 1361 Mb. Screening of BAC pools, followed by the KeyMaps <it>in silico </it>anchoring procedure, identified 1725 AFLP markers in the physical map, and 1252 BAC contigs were anchored the ultradense potato genetic map. A second, sequence-tag-based physical map was constructed from 65919 whole genome profiling (WGP) BAC fingerprints and these were aligned into 3601 BAC contigs spanning 1396 Mb. The 39733 BAC clones that overlap between both physical maps provided anchors to 1127 contigs in the WGP physical map, and reduced the number of contigs to around 2800 in each map separately. Both physical maps were 1.64 times longer than the 850 Mb potato genome. Genome heterozygosity and incomplete merging of BAC contigs are two factors that can explain this map inflation. The contig information of both physical maps was united in a single table that describes hybrid potato physical map.</p> <p>Conclusions</p> <p>The AFLP physical map has already been used by the Potato Genome Sequencing Consortium for sequencing 10% of the heterozygous genome of clone RH on a BAC-by-BAC basis. By layering a new WGP physical map on top of the AFLP physical map, a genetically anchored genome-wide framework of 322434 sequence tags has been created. This reference framework can be used for anchoring and ordering of genomic sequences of clone RH (and other potato genotypes), and opens the possibility to finish sequencing of the RH genome in a more efficient way via high throughput next generation approaches.</p
Parker Solar Probe Observations of High Plasma Beta Solar Wind from Streamer Belt
In general, slow solar wind from the streamer belt forms a high plasma beta
equatorial plasma sheet around the heliospheric current sheet (HCS) crossing,
namely the heliospheric plasma sheet (HPS). Current Parker Solar Probe (PSP)
observations show that the HCS crossings near the Sun could be full or partial
current sheet crossing (PCS), and they share some common features but also have
different properties. In this work, using the PSP observations from encounters
4 to 10, we identify streamer belt solar wind from enhancements in plasma beta,
and we further use electron pitch angle distributions to separate it into HPS
solar wind that around the full HCS crossings and PCS solar wind that in the
vicinity of PCS crossings. Based on our analysis, we find that the PCS solar
wind has different characteristics as compared with HPS solar wind: a) PCS
solar wind could be non-pressure-balanced structures rather than magnetic
holes, and the total pressure enhancement mainly results from the less reduced
magnetic pressure; b) some of the PCS solar wind are mirror unstable; c) PCS
solar wind is dominated by very low helium abundance but varied alpha-proton
differential speed. We suggest the PCS solar wind could originate from coronal
loops deep inside the streamer belt, and it is pristine solar wind that still
actively interacts with ambient solar wind, thus it is valuable for further
investigations on the heating and acceleration of slow solar wind
The Human Minor Histocompatibility Antigen1 Is a RhoGAP
The human minor Histocompatibility Antigen HMHA-1 is a major target of immune responses after allogeneic stem cell transplantation applied for the treatment of leukemia and solid tumors. The restriction of its expression to hematopoietic cells and many solid tumors raised questions regarding its cellular functions. Sequence analysis of the HMHA-1 encoding HMHA1 protein revealed the presence of a possible C-terminal RhoGTPase Activating Protein (GAP) domain and an N-terminal BAR domain. Rho-family GTPases, including Rac1, Cdc42, and RhoA are key regulators of the actin cytoskeleton and control cell spreading and migration. RhoGTPase activity is under tight control as aberrant signaling can lead to pathology, including inflammation and cancer. Whereas Guanine nucleotide Exchange Factors (GEFs) mediate the exchange of GDP for GTP resulting in RhoGTPase activation, GAPs catalyze the low intrinsic GTPase activity of active RhoGTPases, resulting in inactivation. Here we identify the HMHA1 protein as a novel RhoGAP. We show that HMHA1 constructs, lacking the N-terminal region, negatively regulate the actin cytoskeleton as well as cell spreading. Furthermore, we show that HMHA1 regulates RhoGTPase activity in vitro and in vivo. Finally, we demonstrate that the HMHA1 N-terminal BAR domain is auto-inhibitory as HMHA1 mutants lacking this region, but not full-length HMHA1, showed GAP activity towards RhoGTPases. In conclusion, this study shows that HMHA1 acts as a RhoGAP to regulate GTPase activity, cytoskeletal remodeling and cell spreading, which are crucial functions in normal hematopoietic and cancer cells
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