Standardization of clinical procedures has become a desirable objective in contemporary medical practice. To this effect, the Spanish Society of Parenteral and Enteral Nutrition (SENPE) has ...endeavoured to create clinical practice guidelines and/or documents of consensus as well as quality standards in artificial nutrition. As a result, the SENPE´s Standardization Team has put together the "Document of Consensus in Enteral Access for Paediatric Nutritional Support" supported by the Spanish Society of Pediatric Gastroenterology, Hepatology and Nutrition (SEGHNP), the National Association of Pediatric and Neonatal Intensive Care Nursery (ANECIPN), and the Spanish Society of Pediatric Surgery (SECP). The present publication is a reduced version of our work; the complete document will be published as a monographic issue. It analyzes enteral access options in the pediatric patient, reviews the levels of evidence and provides the team-members' experience. Similarly, it details general and specific indications for pediatric enteral support, current techniques, care guidelines, methods of administration and complications of each enteral access. The data published by the American Society for Parenteral and Enteral Nutrition (ASPEN) and several European Societies has also been incorporated.
Background: Neoadjuvant chemotherapy has shown a modest benefit in muscle-invasive bladder cancer patients; however, the subset of patients most likely to benefit has not been identified. BRCA1 plays ...a central role in DNA repair pathways and low BRCA1 expression has been associated with sensitivity to cisplatin and longer survival in lung and ovarian cancer patients.
Patients and methods: We assessed BRCA1 messenger RNA expression levels in paraffin-embedded pre-treatment tumor samples obtained by transurethral resection from 57 patients with locally advanced bladder cancer subsequently treated with neoadjuvant cisplatin-based chemotherapy. BRCA1 levels were divided into terciles and correlated with pathological response and survival.
Results: A significant pathological response (pT0-1) was attained in 66% (24 of 39) of patients with low/intermediate BRCA1 levels compared with 22% (4 of 18) of patients with high BRCA1 levels (P = 0.01). Median survival was 168 months in patients with low/intermediate levels and 34 months in patients with high BRCA1 levels (P = 0.002). In the multivariate analysis for survival, only BRCA1 expression levels and lymphovascular invasion emerged as independent prognostic factors.
Conclusions: Our data suggest that BRCA1 expression may predict the efficacy of cisplatin-based neoadjuvant chemotherapy and may help to customize therapy in bladder cancer patients.
Purpose:
A breast dedicated positron emission tomography (PET) scanner has been developed based on monolithic LYSO crystals coupled to position sensitive photomultiplier tubes (PSPMTs). In this ...study, we describe the design of the PET system and report on its performance evaluation.
Methods:
MAMMI is a breast PET scanner based on monolithic LYSO crystals. It consists of 12 compact modules with a transaxial field of view (FOV) of 170 mm in diameter and 40 mm axial FOV that translates to cover up to 170 mm. The patient lies down in a prone position that facilitates maximum breast elongation. Quantitative performance analysis of the calculated method for the attenuation correction specifically developed for MAMMI, and based on PET image segmentation, has also been conducted in this evaluation. In order to fully determine the MAMMI prototype's performance, we have adapted the measurements suggested for National Electrical Manufacturers Association (NEMA) NU 2-2007 and NU 4-2008 protocol tests, as they are defined for whole-body and small animal PET scanners, respectively.
Results:
Spatial resolutions of 1.6, 1.8, and 1.9 mm were measured in the axial, radial, and tangential directions, respectively. A scatter fraction of 20.8% was obtained and the maximum NEC was determined to be 25 kcps at 44 MBq. The average sensitivity of the system was observed to be 1% for an energy window of (250 keV–750 keV) and a maximum absolute sensitivity of 1.8% was measured at the FOV center.
Conclusions:
The overall performance of the MAMMI reported on this evaluation quantifies its ability to produce high quality PET images. Spatial resolution values below 3 mm were measured in most of the FOV. Only the radial component of spatial resolution exceeds the 3 mm at radial positions larger than 60 mm. This study emphasizes the need for standardized testing methodologies for dedicated breast PET systems similar to NEMA standards for whole-body and small animal PET scanners.
Eleven- to twenty-day-old intact sunflower plants (
Helianthus annuus L. cv. Sun-Gro 380) grown in nutrient solutions with different K
+ levels were used to study the effect of K
+ status and ...abscisic acid (ABA) on water flow. Changes in nutrient potassium levels prompted no significant changes in growth, although there were evident differences in internal K
+ content and water uptake capacity. Water uptake was greater, and water use less efficient, in moderately K
+ deficient plants than in controls. Addition of 4
μM ABA to the external medium induced a differential effect between the two types of plant, inhibiting water uptake more effectively in plants with normal K
+ status. The effect of internal K
+ content on xylem sap pH was also studied, pH was more acidic in moderately K
+ deficient plants than in controls. These results suggest that water flux regulation could be impaired in K
+-starved plants.
Purpose:
The authors have developed a trimodal PET/SPECT/CT scanner for small animal imaging. The gamma ray subsystems are based on monolithic crystals coupled to multianode photomultiplier tubes ...(MA-PMTs), while computed tomography (CT) comprises a commercially available microfocus x-ray tube and a CsI scintillator 2D pixelated flat panel x-ray detector. In this study the authors will report on the design and performance evaluation of the multimodal system.
Methods:
X-ray transmission measurements are performed based on cone-beam geometry. Individual projections were acquired by rotating the x-ray tube and the 2D flat panel detector, thus making possible a transaxial field of view (FOV) of roughly 80 mm in diameter and an axial FOV of 65 mm for the CT system. The single photon emission computed tomography (SPECT) component has a dual head detector geometry mounted on a rotating gantry. The distance between the SPECT module detectors can be varied in order to optimize specific user requirements, including variable FOV. The positron emission tomography (PET) system is made up of eight compact modules forming an octagon with an axial FOV of 40 mm and a transaxial FOV of 80 mm in diameter. The main CT image quality parameters (spatial resolution and uniformity) have been determined. In the case of the SPECT, the tomographic spatial resolution and system sensitivity have been evaluated with a99mTc solution using single-pinhole and multi-pinhole collimators. PET and SPECT images were reconstructed using three-dimensional (3D) maximum likelihood and ordered subset expectation maximization (MLEM and OSEM) algorithms developed by the authors, whereas the CT images were obtained using a 3D based FBP algorithm.
Results:
CT spatial resolution was 85μm while a uniformity of 2.7% was obtained for a water filled phantom at 45 kV. The SPECT spatial resolution was better than 0.8 mm measured with a Derenzo-like phantom for a FOV of 20 mm using a 1-mm pinhole aperture collimator. The full width at half-maximum PET radial spatial resolution at the center of the field of view was 1.55 mm. The SPECT system sensitivity for a FOV of 20 mm and 15% energy window was 700 cps/MBq (7.8 × 10−2%) using a multi-pinhole equipped with five apertures 1 mm in diameter, whereas the PET absolute sensitivity was 2% for a 350–650 keV energy window and a 5 ns timing window. Several animal images are also presented.
Conclusions:
The new small animal PET/SPECT/CT proposed here exhibits high performance, producing high-quality images suitable for studies with small animals. Monolithic design for PET and SPECT scintillator crystals reduces cost and complexity without significant performance degradation.
The benefit of azacitidine treatment in survival of high-risk myelodysplastic syndromes (MDS) patients compared with conventional care treatment (CCT) has not been established outside clinical ...trials. To assess its effectiveness, we compared overall survival (OS) between azacitidine and conventional treatment (CCT) in high-risk MDS patients, excluding those undergoing stem cell transplantation, submitted to the Spanish MDS registry from 2000 to 2013. Several Cox regression and competing risk models, considering azacitidine as a time-dependent covariate, were used to assess survival and acute myeloblastic leukemia (AML) progression. Among 821 patients included, 251 received azacitidine. Median survival was 13.4 (11.8-16) months for azacitidine-treated patients and 12.2 (11-14.1) for patients under CCT (P=0.41). In a multivariate model, age, International prognostic scoring system and lactate dehydrogenase were predictors of OS whereas azacitidine was not (adjusted odds ratio 1.08, 95% confidence interval 0.86-1.35, P=0.49). However, in patients with chromosome 7 abnormalities, a trend toward a better survival was observed in azacitidine-treated patients (median survival 13.3 (11-18) months) compared with CCT (median survival 8.6 (5-10.4) months, P=0.08). In conclusion, our data show that, in spite of a widespread use of azacitidine, there is a lack of improvement in survival over the years. Identification of predicting factors of response and survival is mandatory.
Purpose:
The authors have developed a small animal Positron emission tomography (PET) scanner based on monolithic LYSO crystals coupled to multi-anode photomultiplier tubes (MA-PMTs). In this study, ...the authors report on the design, calibration procedure, and performance evaluation of a PET system that the authors have developed using this innovative nonpixelated detector design.
Methods
: The scanner is made up of eight compact modules forming an octagon with an axial field of view (FOV) of 40 mm and a transaxial FOV of 80 mm diameter. In order to fully determine its performance, a recently issued National Electrical Manufacturers Association (NEMA) NU-4 protocol, specifically developed for small animal PET scanners, has been followed. By measuring the width of light distribution collected in the MA-PMT the authors are able to determine depth of interaction (DOI), thus making the proper identification of lines of response (LORs) with large incidence angles possible. PET performances are compared with those obtained with currently commercially available small animal PET scanners.
Results
: At axial center when the point-like source is located at 5 mm from the radial center, the spatial resolution measured was 1.65, 1.80, and 1.86 mm full width at half maximum (FWHM) for radial, tangential, and axial image profiles, respectively. A system scatter fraction of 7.5% (mouse-like phantom) and 13% (rat-like phantom) was obtained, while the maximum noise equivalent count rate (NECR) was 16.9 kcps at 12.7 MBq (0.37 MBq/ml) for mouse-like phantom and 12.8 kcps at 12.4 MBq (0.042 MBq/ml) for rat-like phantom The peak absolute sensitivity in the center of the FOV is 2% for a 30% peak energy window. Several animal images are also presented.
Conclusions:
The overall performance of our small animal PET is comparable to that obtained with much more complex crystal pixelated PET systems. Moreover, the new proposed PET produces high-quality images suitable for studies with small animals.
Laser-plasma interactions at high intensities are often accompanied by emission of a strong electromagnetic pulse (EMP) interfering with particle detectors or other electronic equipment. We present ...experimental evidence for significant differences in noise amplitudes in laser-proton acceleration from aluminium as compared to mylar target foils. Such dissimilarities have been consistently observed throughout two series of measurements indicating that, under otherwise identical conditions, the target conductivity is the principal parameter related to EMP generation. In addition, the lateral size of the target foils correlates with the absolute noise levels. A frequency analysis combined with numerical simulations allows for an identification of several sources of radiofrequency emission in the MHz-GHz regime. Further, the temporal evolution of single frequencies on the nanosecond scale provides information on distinct excitation mechanisms.
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