203 research outputs found
Relationship of (99m)technetium labelled macroaggregated albumin ((99m)Tc-MAA) uptake by colorectal liver metastases to response following Selective Internal Radiation Therapy (SIRT)
BACKGROUND: SIRT is an emerging treatment for liver tumours which relies on the selective uptake by tumour of (90)Y microspheres following hepatic arterial injection. Response rates of around 90% are reported. Hepatic arterial injection of MAA gives an indication of the expected distribution of (90)Y microspheres within the liver. This study sought to determine if the MAA scan could be predictive of subsequent tumour response. METHODS: 58 patients with colorectal hepatic metastases received SIRT. All had pre-treatment MAA planar images and CT scans which were retrospectively reviewed. Tumours were qualitatively considered "cold", "equivocal" or "hot" based on MAA uptake and the ratio of uptake in tumour and normal liver tissue was calculated (TNR). Following SIRT (which included the administration of hepatic arterial Angiotensin 2) tumour response was assessed by CEA changes one to two months after treatment and by serial CT. RESULTS: Uptake was classified as "hot" in 37 patients (Group 1) and "equivocal" or "cold" in 21 (Group 2). CEA levels fell dramatically in over 90% of patients. The falls were not significantly different between the groups. There was no correlation between TNR and tumour response based on CEA changes (r(2 )= 0.004). CT responses after 3 months were not different in the 2 Groups. CONCLUSION: The pattern of MAA uptake by colorectal liver tumours after arterial injection is not a predictor of tumour response after treatment by SIRT. The results suggest the doses of (90)Y microspheres used may be greater than is necessary
Selective Internal Radiation Therapy for Gastrointestinal Neuroendocrine Tumour Liver Metastases: A New and Effective Modality for Treatment
Background. Nonresectable neuroendocrine tumour (NET) liver metastases respond poorly to most widely available and used therapies. Selective Internal Radiation Therapy (SIRT) is becoming recognized as a new modality for selectively treating non-resectable liver tumours. This paper presents an experience of 14 patients with non-resectable NET liver metastases treated with SIRT.
Methods. Between September 1997 and October 2009 14 patients with extensive NET liver metastases were treated with 2.0 to 3.0 GBq of 90Yttrium microspheres. Repeat SIRT was undertaken in three patients after 16, 27, and 48 months, respectively. Responses were assessed clinically, biochemically, and with serial CT scans. Survival was measured from initial SIRT.
Results. Some response was seen in all 14 patients. Carcinoid syndrome improved or resolved in 10/10 instances. 24-hour urinary 5-HIAA or serum chromogranin A levels fell dramatically in 5/7 patients following SIRT. Serial CT scans revealed partial response or stable disease in all 14 patients. Repeat treatment in three patients experiencing progression was associated with a further response. Median survival after SIRT is 25 months with 6 patients being alive (and 3 patients still asymptomatic), at 19, 22, 23, 23, 58, and 60 months. Conclusions. SIRT is an effective and well-tolerated treatment for non-resectable NET liver metastases capable of both alleviating the carcinoid syndrome and achieving significant tumour regression. Repeat treatment is an option and liver resection after downstaging may also become possible
Hepatic Cryotherapy and Subsequent Hepatic Arterial Chemotherapy for Colorectal Metastases to the Liver
This paper presents an experience of thirty consecutive
patients with hepatic colorectal metastases
who were treated with hepatic cryotherapy and
subsequent hepatic arterial infusion (HAI) chemotherapy
using 5FU
Lunar dust characterization by polarimetric signature. I. Negative polarization branch of sphere aggregates of various porosities
Context. In support of NASA's exploration program and the return to the Moon,
the polarimetric signature of dispersed individual Lunar regolith dust grains
is studied to enable the characterization of the dust exopsheric environment by
remote, in-situ, and standoff sensing. Aims. We explore the value of the
negative polarization branch (NPB) as a signature for characterizing individual
grains to determine if it can be used in the same way as for surfaces of
planets and atmosphereless bodies. Results. Calculations show that polarization
phase curves for spherical grains exhibit a sharp transition over a narrow
range of size parameter between two distinct regimes, one typical of Rayleigh
scattering and another dominated by a large NPB. The linear polarimetric
signature observed for aggregates is a composite of a) the polarization induced
by individual grains composing the aggregate and b) the polarization due to the
aggregate as a whole dust grain. The weight of each component varies depending
on the porosity of the aggregate. An NPB similar to the one observed for
atmosphereless astronomical bodies is present for different ranges of the size
parameter depending on the value of the porosity. It appears as a remnant of
the negative branch exhibited by the single spherical grains. The sharper,
narrow negative branch that is measured for some granular surfaces in the
laboratory or seen in astronomical observations is not observed here.Comment: 7 pages, 8 figures, accepted for publication in Astronomy &
Astrophysic
Lunar Surface Electric Potential Changes Associated with Traversals through the Earth's Foreshock
We report an analysis of one year of Suprathermal Ion Detector Experiment (SIDE) Total Ion Detector (TID) resonance events observed between January 1972 and January 1973. The study includes only those events during which upstream solar wind conditions were readily available. The analysis shows that these events are associated with lunar traversals through the dawn flank of the terrestrial magnetospheric bow shock. We propose that the events result from an increase in lunar surface electric potential effected by secondary electron emission due to primary electrons in the Earth's foreshock region (although primary ions may play a role as well). This work establishes (1) the lunar surface potential changes as the Moon moves through the terrestrial bow shock, (2) the lunar surface achieves potentials in the upstream foreshock region that differ from those in the downstream magnetosheath region, (3) these differences can be explained by the presence of energetic electron beams in the upstream foreshock region and (4) if this explanation is correct, the location of the Moon with respect to the terrestrial bow shock influences lunar surface potential
23 High Redshift Supernovae from the IfA Deep Survey: Doubling the SN Sample at z>0.7
We present photometric and spectroscopic observations of 23 high redshift
supernovae spanning a range of z=0.34-1.03, 9 of which are unambiguously
classified as Type Ia. These supernovae were discovered during the IfA Deep
Survey, which began in September 2001 and observed a total of 2.5 square
degrees to a depth of approximately m=25-26 in RIZ over 9-17 visits, typically
every 1-3 weeks for nearly 5 months, with additional observations continuing
until April 2002. We give a brief description of the survey motivations,
observational strategy, and reduction process. This sample of 23 high-redshift
supernovae includes 15 at z>0.7, doubling the published number of objects at
these redshifts, and indicates that the evidence for acceleration of the
universe is not due to a systematic effect proportional to redshift. In
combination with the recent compilation of Tonry et al. (2003), we calculate
cosmological parameter density contours which are consistent with the flat
universe indicated by the CMB (Spergel et al. 2003). Adopting the constraint
that Omega_total = 1.0, we obtain best-fit values of (Omega_m,
Omega_Lambda)=(0.33, 0.67) using 22 SNe from this survey augmented by the
literature compilation. We show that using the empty-beam model for
gravitational lensing does not eliminate the need for Omega_Lambda > 0.
Experience from this survey indicates great potential for similar large-scale
surveys while also revealing the limitations of performing surveys for z>1 SNe
from the ground.Comment: 67 pages, 12 figures, 12 tables, accepted for publication in the
Astrophysical Journa
Nutritional Ketosis Alters Fuel Preference and Thereby Endurance Performance in Athletes.
Ketosis, the metabolic response to energy crisis, is a mechanism to sustain life by altering oxidative fuel selection. Often overlooked for its metabolic potential, ketosis is poorly understood outside of starvation or diabetic crisis. Thus, we studied the biochemical advantages of ketosis in humans using a ketone ester-based form of nutrition without the unwanted milieu of endogenous ketone body production by caloric or carbohydrate restriction. In five separate studies of 39 high-performance athletes, we show how this unique metabolic state improves physical endurance by altering fuel competition for oxidative respiration. Ketosis decreased muscle glycolysis and plasma lactate concentrations, while providing an alternative substrate for oxidative phosphorylation. Ketosis increased intramuscular triacylglycerol oxidation during exercise, even in the presence of normal muscle glycogen, co-ingested carbohydrate and elevated insulin. These findings may hold clues to greater human potential and a better understanding of fuel metabolism in health and disease
Observational and Dynamical Characterization of Main-Belt Comet P/2010 R2 (La Sagra)
We present observations of comet-like main-belt object P/2010 R2 (La Sagra)
obtained by Pan-STARRS 1 and the Faulkes Telescope-North on Haleakala in
Hawaii, the University of Hawaii 2.2 m, Gemini-North, and Keck I telescopes on
Mauna Kea, the Danish 1.54 m telescope at La Silla, and the Isaac Newton
Telescope on La Palma. An antisolar dust tail is observed from August 2010
through February 2011, while a dust trail aligned with the object's orbit plane
is also observed from December 2010 through August 2011. Assuming typical phase
darkening behavior, P/La Sagra is seen to increase in brightness by >1 mag
between August 2010 and December 2010, suggesting that dust production is
ongoing over this period. These results strongly suggest that the observed
activity is cometary in nature (i.e., driven by the sublimation of volatile
material), and that P/La Sagra is therefore the most recent main-belt comet to
be discovered. We find an approximate absolute magnitude for the nucleus of
H_R=17.9+/-0.2 mag, corresponding to a nucleus radius of ~0.7 km, assuming an
albedo of p=0.05. Using optical spectroscopy, we find no evidence of
sublimation products (i.e., gas emission), finding an upper limit CN production
rate of Q_CN<6x10^23 mol/s, from which we infer an H2O production rate of
Q_H2O<10^26 mol/s. Numerical simulations indicate that P/La Sagra is
dynamically stable for >100 Myr, suggesting that it is likely native to its
current location and that its composition is likely representative of other
objects in the same region of the main belt, though the relatively close
proximity of the 13:6 mean-motion resonance with Jupiter and the (3,-2,-1)
three-body mean-motion resonance with Jupiter and Saturn mean that dynamical
instability on larger timescales cannot be ruled out.Comment: 23 pages, 13 figures, accepted for publication in A
Wild Blueberries 1999 CSREES Progress Reports
The 1999 edition of the Wild Blueberries CSREES Progress Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Effects of QF Processing on Microbiological Quality of Maine Wild Blueberries
2. Separation of Maggot-Infested Blueberries in the IQF Processing Line
3. Determination of Pesticide Residue Levels in Fresh and Processed Wild Blueberries
4. Control Tactics for Blueberry Pest Insects
5. IPM Strategies
6. Biology and Ecology of Blueberry Pest Insects
7. Survey of Stem Blight and Leaf Spot Diseases in Lowbush Blueberry Fields
8. Phosphorus/Nitrogen Fertilizer Ratio
9. Effect of Fertilizer Timing on Lowbush Blueberry Growth and Productivity
10. Effect of Soil pH on Nutrient Uptake
11. Effect of Boron Application Methods on Boron Uptake in Lowbush Blueberries
12. Effect of Nutri-Phite P+K on growth and yield of lowbush blueberry
13. Effect of Crop-Set on growth and yield of lowbush blueberry
14. Crop year fertilization of lowbush blueberry
15. Alternative Methods of Grass Control
16. Cultural Weed Management Using pH
17. Investigation of Hexazinone Alternatives for Weed Control
18. Comparison of Sulfosate and Glyphosate for Weed Control
19. Evaluation of VC1447 for Weed Control in Wild blueberries
20. Blueberry/ Cranberry Extension Education Program in 1999
21. Effect of Rate, Formulation and Application Method on Efficacy and Phytotoxicity of Granular Hexazinone in Wild Blueberry Fields
22. 1999 Fungicide Evaluation Field Trial
23. 1999 Hexazinone Groundwater Survey Pollination
24. Sustainable Pollination of Wild Blueberr
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