Prostate cancer diagnosis and treatment continues to be a major public health challenge. The heterogeneity of the disease is one of the major factors leading to imprecise diagnosis and suboptimal ...disease management. The improved resolution of functional multi-parametric magnetic resonance imaging (mpMRI) has shown promise to improve detection and characterization of the disease. Regions that subdivide the tumor based on Dynamic Contrast Enhancement (DCE) of mpMRI are referred to as
in this study. The DCE defined perfusion curve patterns on the identified tumor habitat region are used to assess clinical significance. These perfusion curves were systematically quantified using seven features in association with the patient biopsy outcome and classifier models were built to find the best discriminating characteristics between clinically significant and insignificant prostate lesions defined by Gleason score (GS). Multivariable analysis was performed independently on one institution and validated on the other, using a multi-parametric feature model, based on DCE characteristics and ADC features. The models had an intra institution Area under the Receiver Operating Characteristic (AUC) of 0.82. Trained on Institution I and validated on the cohort from Institution II, the AUC was also 0.82 (sensitivity 0.68, specificity 0.95).
Magnetic resonance (MR) imaging and computed tomography (CT) are used almost exclusively in radiation therapy planning of glioblastoma multiforme (GBM), despite their well-recognized limitations. MR ...spectroscopic imaging (MRSI) can identify biochemical patterns associated with normal brain and tumor, predominantly by observation of choline (Cho) and N-acetylaspartate (NAA) distributions. In this study, volumetric 3-dimensional MRSI was used to map these compounds over a wide region of the brain and to evaluate metabolite-defined treatment targets (metabolic tumor volumes MTV).
Volumetric MRSI with effective voxel size of ∼1.0 mL and standard clinical MR images were obtained from 19 GBM patients. Gross tumor volumes and edema were manually outlined, and clinical target volumes (CTVs) receiving 46 and 60 Gy were defined (CTV46 and CTV60, respectively). MTVCho and MTVNAA were constructed based on volumes with high Cho and low NAA relative to values estimated from normal-appearing tissue.
The MRSI coverage of the brain was between 70% and 76%. The MTVNAA were almost entirely contained within the edema, and the correlation between the 2 volumes was significant (r=0.68, P=.001). In contrast, a considerable fraction of MTVCho was outside of the edema (median, 33%) and for some patients it was also outside of the CTV46 and CTV60. These untreated volumes were greater than 10% for 7 patients (37%) in the study, and on average more than one-third (34.3%) of the MTVCho for these patients were outside of CTV60.
This study demonstrates the potential usefulness of whole-brain MRSI for radiation therapy planning of GBM and revealed that areas of metabolically active tumor are not covered by standard RT volumes. The described integration of MTV into the RT system will pave the way to future clinical trials investigating outcomes in patients treated based on metabolic information.
Purpose
This study aimed to develop an automated procedure for identifying suspicious foci of residual/recurrent disease in the prostate bed using dynamic contrast-enhanced-MRI (DCE-MRI) in prostate ...cancer patients after prostatectomy.
Materials and methods
Data of 22 patients presenting for salvage radiotherapy (RT) with an identified gross tumor volume (GTV) in the prostate bed were analyzed retrospectively. An unsupervised pattern recognition method was used to analyze DCE-MRI curves from the prostate bed. Data were represented as a product of a number of signal-vs.-time patterns and their weights. The temporal pattern, characterized by fast wash-in and gradual wash-out, was considered the “tumor” pattern. The corresponding weights were thresholded based on the number (1, 1.5, 2, 2.5) of standard deviations away from the mean, denoted as DCE1.0, …, DCE2.5, and displayed on the T2-weighted MRI. The resultant four volumes were compared with the GTV and maximum pre-RT prostate-specific antigen (PSA) level. Pharmacokinetic modeling was also carried out.
Results
Principal component analysis determined 2–4 significant patterns in patients’ DCE-MRI. Analysis and display of the identified suspicious foci was performed in commercial software (MIM Corporation, Cleveland, OH, USA). In general, DCE1.0/DCE1.5 highlighted larger areas than GTV. DCE2.0 and GTV were significantly correlated (r = 0.60,
p
< 0.05). DCE2.0/DCA2.5 were also significantly correlated with PSA (r = 0.52, 0.67,
p
< 0.05). K
trans
for DCE2.5 was statistically higher than the GTV’s K
trans
(
p
< 0.05), indicating that the automatic volume better captures areas of malignancy.
Conclusion
A software tool was developed for identification and visualization of the suspicious foci in DCE-MRI from post-prostatectomy patients and was integrated into the treatment planning system.
Mapping of glycine distributions in gliomas Maudsley, A A; Gupta, R K; Stoyanova, R ...
American journal of neuroradiology : AJNR,
06/2014, Letnik:
35, Številka:
6 Suppl
Journal Article
Recenzirano
Odprti dostop
Increased glycine concentration in the brain is associated with altered metabolism in cancer and can be detected by using in vivo MR spectroscopy. This has been proposed as a marker for grade IV ...gliomas; however, little is known about the potential significance and frequency of in vivo glycine observation. The purpose of this study was to examine the rate of occurrence and spatial distribution of glycine observation with respect to other MR imaging parameters.
Data from volumetric whole-brain MR spectroscopic imaging of 59 subjects with glioma were analyzed with glycine included in the spectral model. The associations of the signal amplitude and spatial distributions of glycine with findings from contrast-enhanced T1, perfusion, and diffusion MR imaging were then examined.
Glycine was detected in 24% of all studies, though with a wide range of signal amplitude and extent of the spatial distributions. While more commonly seen in grade IV tumors (42% of studies), relatively large concentrations were also detected in grade II and III gliomas. Coanalysis with other metabolites indicated a strong association with choline and that glycine was frequently seen to be overlapping with, and adjacent to, areas of high lactate concentration. Increased glycine was always associated with contrast enhancement and areas of increased cerebral blood flow, but without any clear association with other image parameters.
Detection of increased glycine in gliomas appears to identify a subgroup of tumors and areas of increased proliferation.
Background
SARS‐CoV‐2 virus requires host proteases to cleave its spike protein to bind to its ACE2 target through a two‐step furin‐mediated entry mechanism. Aprotinin is a broad‐spectrum protease ...inhibitor that has been employed as antiviral drug for other human respiratory viruses. Also, it has important anti‐inflammatory properties for inhibiting the innate immunity contact system.
Methods
This was a multicentre, double‐blind, randomized trial performed in four Spanish hospitals comparing standard treatment versus standard treatment + aprotinin for patients with COVID‐19 between 20 May 2020 and 20 October 2021. The primary efficacy outcomes were length of hospital stay and ICU admission. The secondary endpoints were each of the primary efficacy outcomes and a composite of oxygen therapy, analytical parameters and death. Safety outcomes included adverse reactions to treatment during a 30‐day follow‐up period. Treatment was given for 11 days or till discharge.
Results
With almost identical analytical profiles, significant differences were observed in treatment time, which was 2 days lower in the aprotinin group (p = .002), and length of hospital admission, which was 5 days shorter in the aprotinin group (p = .003). The incidence of discharge was 2.19 times higher (HR: 2.188 1.182–4.047) in the aprotinin group than in the placebo group (p = .013). In addition, the aprotinin‐treated group required less oxygen therapy and had no adverse reactions or side effects.
Conclusion
Inhaled aprotinin may improve standard treatment and clinical outcomes in hospitalized patients with COVID‐19, resulting in a shorter treatment time and hospitalization compared with the placebo group. The administration of aprotinin was safe.
Although coronavirus disease 2019 (COVID-19) has affected endoscopy services globally, the impact on trainees has not been evaluated. We aimed to assess the impact of COVID-19 on procedural volumes ...and on the emotional well-being of endoscopy trainees worldwide.
An international survey was disseminated over a 3-week period in April 2020. The primary outcome was the percentage reduction in monthly procedure volume before and during COVID-19. Secondary outcomes included potential variation of COVID-19 impact between different continents and rates and predictors of anxiety and burnout among trainees.
Across 770 trainees from 63 countries, 93.8% reported a reduction in endoscopy case volume. The median percentage reduction in total procedures was 99% (interquartile range, 85%-100%), which varied internationally (P < .001) and was greatest for colonoscopy procedures. Restrictions in case volume and trainee activity were common barriers. A total of 71.9% were concerned that the COVID-19 pandemic could prolonged training. Anxiety was reported in 52.4% of respondents and burnout in 18.8%. Anxiety was independently associated with female gender (odds ratio OR, 2.15; P < .001), adequacy of personal protective equipment (OR, 1.75; P = .005), lack of institutional support for emotional health (OR, 1.67; P = .008), and concerns regarding prolongation of training (OR, 1.60; P = .013). Modifying existing national guidelines to support adequate endoscopy training during the pandemic was supported by 68.9%.
The COVID-19 pandemic has led to restrictions in endoscopic volumes and endoscopy training, with high rates of anxiety and burnout among endoscopy trainees worldwide. Targeted measures by training programs to address these key issues are warranted to improve trainee well-being and support trainee education.
Summary
Apple pomace (AP) is the by‐product obtained after juice extraction. It is a potential ingredient for the fibre enrichment of foods. In the present work, AP was combined in gluten ...free‐mixtures with cassava starch (CS), rice flour (RF), egg white (EW) and sucrose (SR) to analyse its effect on thermal transitions of starch and the batter and bread crumb microstructures. Model systems with all or part of the main ingredients (CS:RF:AP:EW:SR in 4:4:1:1:1 proportions) and a batter formulation with AP were prepared by dry mixing and then dispersing the solids in water. CLSM allowed observing the distribution of egg proteins, AP and RF particles and CS granules. The batter enriched with AP exhibited higher apparent viscosities and dilatant behaviour. Thermal transitions were analysed by DSC. Endotherms ranged between 57 and 97°C. Gluten‐free bread microstructure was analysed by SEM. A more irregular and compact crumb structure was observed when AP was used, with the air cell walls constituted by gelatinized starch granules and AP particles interpenetrating them. By measuring the firmness of crumb along storage, it could be concluded that amylopectin retrogradation was partially inhibited by the presence of AP in model systems but in bread, this inhibiting effect was not evident.
The tropical Northern Andes constitutes a great area to explore the interaction of tectonics and climate on the evolution of orogenic topography, as they are tectonically active, have steep gradients ...in relief and precipitation, and were less affected by Quaternary glaciations than high‐latitude mountains. This study combines new and published thermochronology along ∼500 km of the Eastern Cordillera in Colombia to explore what controls the rates of Miocene and Pliocene exhumation, including: (1) variations in late Cenozoic paleoclimate, (2) orographic precipitation or (3) variation in rock uplift associated with structural heterogeneities along the eastern flank of the range. New thermochronology data consists of 27 apatite and seven zircon (U‐Th)/He ages and five apatite fission track ages. Thermal history models show that rock cooling as a result of erosional exhumation has occurred everywhere in the Eastern Cordillera since at least the Miocene at spatially and temporally variable rates. Exhumation rates vary by an order of magnitude between various fault‐bounded blocks and there is no evidence for a spatially uniform increase in exhumation rates during the past ∼4–5 Ma that would indicate uniform climatic driven exhumation. The west (dry) to east (wet) gradient in precipitation rates across the Garzon Massif is not a major factor controlling the exhumation rates, as the exhumation rates are highest on the western drier flank. The greatest rates of exhumation of the Eastern Cordillera occur in the blocks associated with vigorous Cenozoic reactivation of inherited faults that had focused extension during Early Cretaceous rifting.
Plain Language Summary
Understanding how tectonic and climatic forces influence erosion and shape mountains is important to understand the evolution of the landscapes through Earth's history. In this work we aim at determining how do tectonic processes and climate variability interact to shape Earth's surface? We studied the Eastern Cordillera of the Northern Andes, a mountain range located in Colombia in the tropics of South America. To obtain erosion (exhumation) rates, we used thermochronology, which is an innovative method that records—over timescales of millions of years—how fast the rocks located at great depths within the earth get cooled as they are transported to the surface while the overlying rock gets removed or eroded from the surface. The results show that the highest erosion rates occur near the places that have the most tectonically active faults. Higher rates of precipitation are not always associated with higher erosion rates. Thus, the precipitation rates along the Eastern Cordillera are not a major factor controlling the erosion rates. This study underscores the importance of a thorough characterization of the location of faults in a region and information about recent fault activity to the understanding of erosion and natural hazards in tropical mountains.
Key Points
Rates and timing of exhumation are spatially variable along the Eastern Cordillera
Precipitation plays a secondary role to tectonics in modulating exhumation
Zones of highest exhumation are associated to inherited structures
Abstract
Batteries that extend performance beyond the intrinsic limits of Li-ion batteries are among the most important developments required to continue the revolution promised by electrochemical ...devices. Of these next-generation batteries, lithium sulfur (Li–S) chemistry is among the most commercially mature, with cells offering a substantial increase in gravimetric energy density, reduced costs and improved safety prospects. However, there remain outstanding issues to advance the commercial prospects of the technology and benefit from the economies of scale felt by Li-ion cells, including improving both the rate performance and longevity of cells. To address these challenges, the Faraday Institution, the UK’s independent institute for electrochemical energy storage science and technology, launched the Lithium Sulfur Technology Accelerator (LiSTAR) programme in October 2019. This Roadmap, authored by researchers and partners of the LiSTAR programme, is intended to highlight the outstanding issues that must be addressed and provide an insight into the pathways towards solving them adopted by the LiSTAR consortium. In compiling this Roadmap we hope to aid the development of the wider Li–S research community, providing a guide for academia, industry, government and funding agencies in this important and rapidly developing research space.
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