bluuebunny/crossref_metadata_2025_split huggingface dataset:
TH‐B‐210A‐01: Determination of Dose to Individual Patients in Radionuclide Imaging Procedures Including Planar, SPECT, and PET
Authors: Williams L 
Published: April 2010

Individual patient absorbed dose estimates are a relatively novel feature in nuclear medicine physics. Historically, almost all estimates were made using phantoms having predetermined geometries and organ sizes. Yet none of their various geometries may be suitable for a given person and other methods are being implemented to allow patient‐specific dose computations. For either phantom or patient‐based estimates, target organ dose is given by the matrix product: D (target organ) = S * Ã (source organs). In the equality, the rectangular matrix S depends upon the energies of emission, their probabilities and the geometry of either the phantom or patient. Ã is a vector containing elements which are the total decays from each source organ. Total decay means essentially an integral over the activity A(MBq) in that source over the time interval 0 ⩽ t ⩽ 8. For an individual, S can sometimes be determined using manipulations of a phantom value for a given radionuclide. In a pure beta or alpha emitter, S becomes diagonal and its elements are proportional to the inverse of the organ mass. This situation is common in targeted radionuclide therapy (TRT) and is the most important application of patient‐specific dose. If the radionuclide emits significant photon radiation, a Monte Carlo approach is probably required to estimate individual organ doses. If one does not correct for target mass, errors in S can approach factors of two to three. This becomes particularly important in some clinical conditions such as lymphoma where the splenic mass may become very large. Determination of Ã is based on measuring activity (A) at‐depth in the patient. At least six techniques are in the literature for activity quantitation. The simplest is single probe counting with corrections for distance such as using inverse‐square law for surface structures. This method, however, cannot be used at‐depth in the patient. Geometric‐mean gamma camera imaging is the most common method of activity quantitation, but suffers from overlapping source organs. Its accuracy is on the order of +/− 30% in phantom and animal studies. The most advanced camera technique is quantitative SPECT imaging. This measurement (QSPECT) is ideally done with hybrid SPECT/CT scanners. Corrections are made for attenuation, scatter, collimator geometry and partial volume effects. Absolute activity accuracy approaches +/− 5% in QSPECT. PET imaging can be competitive with this result if a positron emitter of sufficient half life and emission probability is available for labeling. The ultimate dose uncertainty for a given patient is a quadratic combination of errors due to S and Ã.Learning Objectives:1. Understand use of D = S*Ã for internal emitters.2. Realize that patient‐specific doses are obtainable.3. Know the sizes of uncertainty in activity and S measurements.4. Discover the use of QSPECT and quantitative PET.
TH‐C‐210A‐03: X‐Ray Based Imaging in Neurovascular Intervention — Requirements and Challenges
Authors: Wakhloo A 
Published: April 2010

In the US, 795,000 people are expected to have a new or recurrent stroke in 2009. Ischemic stroke, which accounts for more than 80% of all strokes, carries a severe toll being the 3rd cause of death and the leading cause of disability. The cost of stroke, both direct and indirect, will exceed $60 billion this year alone. Hemorrhagic stroke on the other hand originates from rupture of brain aneurysms, which cause the vast majority of subarachnoid hemorrhage, a devastating medical emergency that affects more than 30,000 Americans each year and causes substantial disability and death.As in the coronary and peripheral vascular system, surgical treatment and medical management is progressively replaced by minimally invasive endovascular treatment. In recent years we have witnessed a rapid advancement in stent and stent‐like technology. Stents do not only serve for a combined intra‐ and extrasaccular treatment of challenging aneurysms, but assist the revascularization in acute and chronic ischemic conditions of the neurovascular system. In the Neuroangiography Suite x‐ray based imaging for guidance of devices and for monitoring brain perfusion during the intervention has experienced a quantum leap. Replacement of Image Intensifiers (II) with Flat Panel Detectors (FD) has enabled to increase the rotational speed of the system and its use as cone beam CT. Today angiography techniques do not only serve to characterize local flow alterations induced by vessel implants, but also study brain perfusion prior and during revascularization maneuvers. Detailed information of vascular structures is provided in conjunction with the surrounding brain tissue and vessel wall. Imaging of temporary or permanent implants is available with high resolution that is vital for a precise placement, treatment efficacy and patient safety.
TH‐C‐213A‐01: Prostate Brachytherapy Ultrasound Quality Assurance Following AAPM TG‐128
Authors: Pfeiffer D , Sutlief S 
Published: April 2010

The goal of AAPM Task Group 128 is to provide guidance to physicists who are responsible for the quality assurance of ultrasound units used in prostate brachytherapy. Accurate imaging guidance and dosimetry calculation for prostate brachytherapy depend upon the quality and accuracy of the ultrasound image. Therefore, a robust quality assurance program for the ultrasound system is essential. Completion of the TG‐128 tests requires use of a specialized ultrasound phantom, a water bath, and other equipment. Some care and creativity is needed to complete these tests. Quality assurance should include each link in the process from ultrasound image acquisition to visualization on the treatment planning system. The recommended tests include grayscale visibility, depth of penetration, axial and lateral resolution, distance measurement, area measurement, volume measurement, needle template/electronic grid alignment, and geometric consistency with the treatment planning computer.Learning Objectives:1. To describe the methods of TG‐128: Quality assurance tests for prostate brachytherapy ultrasound systems2. To highlight special techniques which may be used to accomplish the tests described in TG‐128.3. To assess the relative likelihoods and significance of potential QA findings.4. To review the materials and time needed to complete the TG‐128 tests.
TH‐C‐213A‐02: Preliminary Report On the Application of TG154 Recommendations in the Clinical Setting
Authors: Molloy J 
Published: April 2010

Ultrasound (US) imaging is used in radiotherapy for soft tissue target localization. Its primary application is for prostate localization, but has an evolving role for breast and other treatment sites. Guidance regarding quality assurance of these systems is derived primarily from manufacturer recommendations which vary between systems. US imaging possesses characteristics that differentiate it from other radiotherapy image‐guided localization techniques, including good soft tissue contrast, the absence of additional radiation risk and cost‐effectiveness. Image interpretation can be challenging due to limited penetration depth and image noise. The AAPM charged Task Group 154 to devise quality assurance recommendations for radiotherapy US localization systems.Guidance regarding periodic quality assurance is provided in the report and will be presented. Emphasis is placed on spatial, mechanical and imaging quality assurance techniques. Recommendations regarding initial user training and ongoing competency credentialing are discussed, as well as practical usage issues that have the potential to improve image quality and localization accuracy. The evolution of the role that US imaging plays in radiotherapy localization is discussed in the context of other image‐guidance techniques, including kV imaging and gold seed markers.Learning Objectives:1. Understand the recommended periodic quality assurance procedures for US localization technologies.2. Become familiar with the role of US localization in the context of other image‐guidance techniques.3. Understand the importance and structure of user training programs.
Microbial Links between Sulfate Reduction and Metal Retention in Uranium- and Heavy Metal-Contaminated Soil
Authors: Sitte Jana , Akob Denise M. , Kaufmann Christian , Finster Kai , Banerjee Dipanjan , Burkhardt Eva-Maria , Kostka Joel E. , Scheinost Andreas C. , Büchel Georg , Küsel Kirsten 
Published: April 2010

ABSTRACT

Sulfate-reducing bacteria (SRB) can affect metal mobility either directly by reductive transformation of metal ions, e.g., uranium, into their insoluble forms or indirectly by formation of metal sulfides. This study evaluated
in situ
and biostimulated activity of SRB in groundwater-influenced soils from a creek bank contaminated with heavy metals and radionuclides within the former uranium mining district of Ronneburg, Germany.
In situ
activity of SRB, measured by the
35
SO
4
2−
radiotracer method, was restricted to reduced soil horizons with rates of ≤142 ± 20 nmol cm
−3
day
−1
. Concentrations of heavy metals were enriched in the solid phase of the reduced horizons, whereas pore water concentrations were low. X-ray absorption near-edge structure (XANES) measurements demonstrated that ∼80% of uranium was present as reduced uranium but appeared to occur as a sorbed complex. Soil-based
dsrAB
clone libraries were dominated by sequences affiliated with members of the
Desulfobacterales
but also the
Desulfovibrionales
,
Syntrophobacteraceae
, and
Clostridiales
. [
13
C]acetate- and [
13
C]lactate-biostimulated soil microcosms were dominated by sulfate and Fe(III) reduction. These processes were associated with enrichment of SRB and
Geobacteraceae
; enriched SRB were closely related to organisms detected in soils by using the
dsrAB
marker. Concentrations of soluble nickel, cobalt, and occasionally zinc declined ≤100% during anoxic soil incubations. In contrast to results in other studies, soluble uranium increased in carbon-amended treatments, reaching ≤1,407 nM in solution. Our results suggest that (i) ongoing sulfate reduction in contaminated soil resulted in
in situ
metal attenuation and (ii) the fate of uranium mobility is not predictable and may lead to downstream contamination of adjacent ecosystems.
Nonmagnetotactic Multicellular Prokaryotes from Low-Saline, Nonmarine Aquatic Environments and Their Unusual Negative Phototactic Behavior
Authors: Lefèvre Christopher T. , Abreu Fernanda , Lins Ulysses , Bazylinski Dennis A. 
Published: April 2010

ABSTRACTMagnetotactic multicellular prokaryotes (MMPs) are unique magnetotactic bacteria of theDeltaproteobacteriaclass and the first found to biomineralize the magnetic mineral greigite (Fe3S4). Thus far they have been reported only from marine habitats. We questioned whether MMPs exist in low-saline, nonmarine environments. MMPs were observed in samples from shallow springs in the Great Boiling Springs geothermal field and Pyramid Lake, both located in northwestern Nevada. The temperature at all sites was ambient, and salinities ranged from 5 to 11 ppt. These MMPs were not magnetotactic and did not contain magnetosomes (called nMMPs here). nMMPs ranged from 7 to 11 μm in diameter, were composed of about 40 to 60 Gram-negative cells, and were motile by numerous flagella that covered each cell on one side, characteristics similar to those of MMPs. 16S rRNA gene sequences of nMMPs show that they form a separate phylogenetic branch within the MMP group in theDeltaproteobacteriaclass, probably representing a single species. nMMPs exhibited a negative phototactic behavior to white light and to wavelengths of ≤480 nm (blue). We devised a “light racetrack” to exploit this behavior, which was used to photoconcentrate nMMPs for specific purposes (e.g., DNA extraction) even though their numbers were low in the sample. Our results show that the unique morphology of the MMP is not restricted to marine and magnetotactic prokaryotes. Discovery of nonmagnetotactic forms of the MMP might support the hypothesis that acquisition of the magnetosome genes involves horizontal gene transfer. To our knowledge, this is the first report of phototaxis in bacteria of theDeltaproteobacteriaclass.
Application of Real-Time PCR To Estimate Toxin Production by the Cyanobacterium
Planktothrix
sp
Authors: Ostermaier Veronika , Kurmayer Rainer 
Published: April 2010

ABSTRACT

Quantitative real-time PCR methods are increasingly being applied for the enumeration of toxic cyanobacteria in the environment. However, to justify the use of real-time PCR quantification as a monitoring tool, significant correlations between genotype abundance and actual toxin concentrations are required. In the present study, we aimed to explain the concentrations of three structural variants of the hepatotoxin microcystin (MC) produced by the filamentous cyanobacterium
Planktothrix
sp., [Asp, butyric acid (Dhb)]-microcystin-RR (where RR means two arginines), [Asp, methyl-dehydro-alanine (Mdha)]-microcystin-RR, and [Asp, Dhb]-microcystin-homotyrosine-arginine (HtyR), by the abundance of the microcystin genotypes encoding their synthesis. Three genotypes of microcystin-producing cyanobacteria (denoted the Dhb, Mdha, and Hty genotypes) in 12 lakes of the Alps in Austria, Germany, and Switzerland from 2005 to 2007 were quantified by means of real-time PCR. Their absolute and relative abundances were related to the concentration of the microcystin structural variants in aliquots determined by high-performance liquid chromatography (HPLC). The total microcystin concentrations varied from 0 to 6.2 μg liter
−1
(mean ± standard error [SE] of 0.6 ± 0.1 μg liter
−1
) among the samples, in turn resulting in an average microcystin content in
Planktothrix
of 3.1 ± 0.7 μg mm
−3
biovolume. Over a wide range of the population density (0.001 to 3.6 mm
3
liter
−1
Planktothrix
biovolume), the Dhb genotype and [Asp, Dhb]-MC-RR were most abundant, while the Hty genotype and MC-HtyR were found to be in the lowest proportion only. In general, there was a significant linear relationship between the abundance/proportion of specific microcystin genotypes and the concentration/proportion of the respective microcystin structural variants on a logarithmic scale. We conclude that estimating the abundance of specific microcystin genotypes by quantitative real-time PCR is useful for predicting the concentration of microcystin variants in water.
Using Epstein-Barr Viral Load Assays To Diagnose, Monitor, and Prevent Posttransplant Lymphoproliferative Disorder
Authors: Gulley Margaret L. , Tang Weihua 
Published: April 2010

SUMMARYEpstein-Barr virus (EBV) DNA measurement is being incorporated into routine medical practice to help diagnose, monitor, and predict posttransplant lymphoproliferative disorder (PTLD) in immunocompromised graft recipients. PTLD is an aggressive neoplasm that almost always harbors EBV DNA within the neoplastic lymphocytes, and it is often fatal if not recognized and treated promptly. Validated protocols, commercial reagents, and automated instruments facilitate implementation of EBV load assays by real-time PCR. When applied to either whole blood or plasma, EBV DNA levels reflect clinical status with respect to EBV-related neoplasia. While many healthy transplant recipients have low viral loads, high EBV loads are strongly associated with current or impending PTLD. Complementary laboratory assays as well as histopathologic examination of lesional tissue help in interpreting modest elevations in viral load. Circulating EBV levels in serial samples reflect changes in tumor burden and represent an effective, noninvasive tool for monitoring the efficacy of therapy. In high-risk patients, serial testing permits early clinical intervention to prevent progression toward frank PTLD. Restoring T cell immunity against EBV is a major strategy for overcoming PTLD, and novel EBV-directed therapies are being explored to thwart virus-driven neoplasia.
Schistosomiasis in the People's Republic of China: the Era of the Three Gorges Dam
Authors: McManus Donald P. , Gray Darren J. , Li Yuesheng , Feng Zheng , Williams Gail M. , Stewart Donald , Rey-Ladino Jose , Ross Allen G. 
Published: April 2010

SUMMARY

The potential impact of the Three Gorges Dam (TGD) on schistosomiasis transmission in China has invoked considerable global concern. The TGD will result in changes in the water level and silt deposition downstream, favoring the reproduction of
Oncomelania
snails. Combined with blockages of the Yangtze River's tributaries, these changes will increase the schistosomiasis transmission season within the marshlands along the middle and lower reaches of the Yangtze River. The changing schistosome transmission dynamics necessitate a comprehensive strategy to control schistosomiasis. This review discusses aspects of the epidemiology and transmission of
Schistosoma japonicum
in China and considers the pathology, clinical outcomes, diagnosis, treatment, immunobiology, and genetics of schistosomiasis japonica together with an overview of current progress in vaccine development, all of which will have an impact on future control efforts. The use of synchronous praziquantel (PZQ) chemotherapy for humans and domestic animals is only temporarily effective, as schistosome reinfection occurs rapidly. Drug delivery requires a substantial infrastructure to regularly cover all parts of an area of endemicity. This makes chemotherapy expensive and, as compliance is often low, a less than satisfactory control option. There is increasing disquiet about the possibility that PZQ-resistant schistosomes will develop. Consequently, as mathematical modeling predicts, vaccine strategies represent an essential component in the future control of schistosomiasis in China. With the inclusion of focal mollusciciding, improvements in sanitation, and health education into the control scenario, China's target of reducing the level of schistosome infection to less than 1% by 2015 may be achievable.
The Changing Microbial Epidemiology in Cystic Fibrosis
Authors: LiPuma John J. 
Published: April 2010

SUMMARYInfection of the airways remains the primary cause of morbidity and mortality in persons with cystic fibrosis (CF). This review describes salient features of the epidemiologies of microbial species that are involved in respiratory tract infection in CF. The apparently expanding spectrum of species causing infection in CF and recent changes in the incidences and prevalences of infection due to specific bacterial, fungal, and viral species are described. The challenges inherent in tracking and interpreting rates of infection in this patient population are discussed.
Bacillus cereus, a Volatile Human Pathogen
Authors: Bottone Edward J. 
Published: April 2010

SUMMARYBacillus cereusis a Gram-positive aerobic or facultatively anaerobic, motile, spore-forming, rod-shaped bacterium that is widely distributed environmentally. WhileB. cereusis associated mainly with food poisoning, it is being increasingly reported to be a cause of serious and potentially fatal non-gastrointestinal-tract infections. The pathogenicity ofB. cereus, whether intestinal or nonintestinal, is intimately associated with the production of tissue-destructive exoenzymes. Among these secreted toxins are four hemolysins, three distinct phospholipases, an emesis-inducing toxin, and proteases. The major hurdle in evaluatingB. cereuswhen isolated from a clinical specimen is overcoming its stigma as an insignificant contaminant. Outside its notoriety in association with food poisoning and severe eye infections, this bacterium has been incriminated in a multitude of other clinical conditions such as anthrax-like progressive pneumonia, fulminant sepsis, and devastating central nervous system infections, particularly in immunosuppressed individuals, intravenous drug abusers, and neonates. Its role in nosocomial acquired bacteremia and wound infections in postsurgical patients has also been well defined, especially when intravascular devices such as catheters are inserted. Primary cutaneous infections mimicking clostridial gas gangrene induced subsequent to trauma have also been well documented.B. cereusproduces a potent β-lactamase conferring marked resistance to β-lactam antibiotics. Antimicrobials noted to be effective in the empirical management of aB. cereusinfection while awaiting antimicrobial susceptibility results for the isolate include ciprofloxacin and vancomycin.
Cultivation and Genomic, Nutritional, and Lipid Biomarker Characterization of
Roseiflexus
Strains Closely Related to Predominant
In Situ
Populations Inhabiting Yellowstone Hot Spring Microbial Mats
Authors: van der Meer Marcel T. J. , Klatt Christian G. , Wood Jason , Bryant Donald A. , Bateson Mary M. , Lammerts Laurens , Schouten Stefan , Sinninghe Damsté Jaap S. , Madigan Michael T. , Ward David M. 
Published: April 2010

ABSTRACT

Roseiflexus
sp. strains were cultivated from a microbial mat of an alkaline siliceous hot spring in Yellowstone National Park. These strains are closely related to predominant filamentous anoxygenic phototrophs found in the mat, as judged by the similarity of small-subunit rRNA, lipid distributions, and genomic and metagenomic sequences. Like a Japanese isolate,
R. castenholzii
, the Yellowstone isolates contain bacteriochlorophyll
a
, but not bacteriochlorophyll
c
or chlorosomes, and grow photoheterotrophically or chemoheterotrophically under dark aerobic conditions. The genome of one isolate,
Roseiflexus
sp. strain RS1, contains genes necessary to support these metabolisms. This genome also contains genes encoding the 3-hydroxypropionate pathway for CO
2
fixation and a hydrogenase, which might enable photoautotrophic metabolism, even though neither isolate could be grown photoautotrophically with H
2
or H
2
S as a possible electron donor. The isolates exhibit temperature, pH, and sulfide preferences typical of their habitat. Lipids produced by these isolates matched much better with mat lipids than do lipids produced by
R. castenholzii
or
Chloroflexus
isolates.
The effects of an exercise intervention on forward head and rounded shoulder postures in elite swimmers
Authors: Lynch Stephanie S , Thigpen Charles A , Mihalik Jason P , Prentice William E , Padua Darin 
Published: April 2010

ObjectivesTo examine the correction of posture, increase in strength and decrease in shoulder pain and dysfunction in varsity swimmers.Design and SettingRandomised clinical trial.ParticipantsTwenty-eightNational Collegiate Athletic Associationdivision I varsity swimmers.MeasurementsTwo testing sessions were conducted before and after an 8-week time period. Posture, strength and shoulder pain and function were assessed. Forward head angle was measured using a digital inclinometer, forward head translation was measured using a ruler and total scapular distance was measured with unmarked string. Average and peak values (N) of strength were measured with the hand-held dynamometer. The intervention subjects then participated in an 8-week exercise training programme to correct posture. The procedures were then repeated in the post-test.ResultsSignificant group by time interactions (p<0.05) were found in forward head angle and forward shoulder translation indicating a decrease in forward head angle and forward shoulder translation. Significant main effects for time (p<0.05) were found in strength measures for all muscle groups indicating increased strength for shoulder girdle muscles tested.ConclusionsThe exercise intervention was successful at decreasing forward head and rounded shoulder postures in elite swimmers. This study supports the theoretical basis for clinical rehabilitation of posture and the shoulder.