1,430 research outputs found
Three Endocrine Neoplasms: An Unusual Combination of Pheochromocytoma, Pituitary Adenoma, and Papillary Thyroid Carcinoma
Background: Three endocrine neoplasms?bilateral pheochromocytomas, somatotrophic pituitary adenoma inducing acromegaly, and papillary carcinoma of the thyroid?occurred concurrently in a patient. A genetic mutation was hypothesized. Possible previously described genetic mutations were explored. Methods: Clinical assessments, laboratory data, images of tumors, histopathology, and immunohistochemistry of excised tissues documented the three neoplasms. Clinical assessment of the patient, family history, and a review of the literature sought a familial basis for the disorders. Results: The methods confirmed the presence of three endocrine neoplasms. Each neoplasm was surgically excised and histologically verified. Surgical and 131I treatments reduced the papillary carcinoma, but eventually this tumor progressed to a lethal degree. History, including that of nine siblings, uncovered no familial neoplasms. No similar case was found in the literature, but possible associations with germline mutations were considered. Conclusions: The concurrent development of pheochromocytomas, pituitary somatotrophic adenoma, and papillary thyroid carcinoma appears to be unique. Nevertheless, such tumors, particularly bilateral pheochromocytomas, strongly suggest a de novo germline mutation in a gene not previously associated with multiple endocrine neoplasia syndromes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98488/1/thy%2E2011%2E0345.pd
Black Cutworm Scouting Advisory
With the unseasonably warm temperatures occurring earlier this year, we asked black cutworm monitoring participants to place moth traps during the end of March. The first moth was recorded in Muscatine County on March 20. Peak flights have been reported by cooperators in many parts of Iowa this year. Our predictions of cutting dates (the date when black cutworm larvae are likely to be damaging corn) are based on recorded peak flights which took place near the end of March and approximately two weeks later in Iowa. The map (Fig. 1) shows the predicted cutting dates for Iowa climate divisions. Where there are two dates, the top date is an estimate based on moth captures that occurred near the end of March; all other dates are based on mid-April captures
Thyroid Carcinoma Metastasis to Skull with Infringement of Brain: Treatment with Radioiodine
Background: Infringement by differentiated thyroid carcinoma on the brain is rare but, when suspected, the patient deserves special attention. A patient with an enlarging metastasis of thyroid carcinoma to the skull that was impinging on the brain illustrates diagnostic and therapeutic strategies applicable to the treatment of metastatic carcinoma. Methods: A case study was performed. Computed tomography (CT) and magnetic resonance imaging (MRI) were done, serum thyroglobulin was measured, and tumor responses to thyroxine and 131I treatments were monitored. Tumor dosimetry, enabled by scintigraphy with 131I employing single photon emission tomography fused with CT (SPECT-CT), was performed. Results: The metastasis was from a follicular variant of papillary thyroid carcinoma. During thyrotropin stimulation the tumor enlarged. The tumor decreased in volume after each of two 131I therapies. Dosimetry indicated delivery of 1970 and 2870cGy to the tumor and 35 and 42cGy to the brain, respectively, in the two treatments. The patient has survived for more than 11 years since diagnosis. Conclusions: A metastasis from a follicular variant of papillary carcinoma increased in volume during hypothyroidism producing more infringement on the brain. Beyond the effects of thyroxine therapy, 131I treatments induced recession of tumor volume. In patients with metastases that concentrate 131I, dosimetry with SPECT-CT can predict absorbed doses of radiation to the tumor and to the adjacent organs and thus lay a basis for data-based decisions on 131I therapies. Therapy may induce prolonged survival in patients with metastases infringing on the brain.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78102/1/thy.2008.0426.pd
Bayesian Parameter Estimation for Latent Markov Random Fields and Social Networks
Undirected graphical models are widely used in statistics, physics and
machine vision. However Bayesian parameter estimation for undirected models is
extremely challenging, since evaluation of the posterior typically involves the
calculation of an intractable normalising constant. This problem has received
much attention, but very little of this has focussed on the important practical
case where the data consists of noisy or incomplete observations of the
underlying hidden structure. This paper specifically addresses this problem,
comparing two alternative methodologies. In the first of these approaches
particle Markov chain Monte Carlo (Andrieu et al., 2010) is used to efficiently
explore the parameter space, combined with the exchange algorithm (Murray et
al., 2006) for avoiding the calculation of the intractable normalising constant
(a proof showing that this combination targets the correct distribution in
found in a supplementary appendix online). This approach is compared with
approximate Bayesian computation (Pritchard et al., 1999). Applications to
estimating the parameters of Ising models and exponential random graphs from
noisy data are presented. Each algorithm used in the paper targets an
approximation to the true posterior due to the use of MCMC to simulate from the
latent graphical model, in lieu of being able to do this exactly in general.
The supplementary appendix also describes the nature of the resulting
approximation.Comment: 26 pages, 2 figures, accepted in Journal of Computational and
Graphical Statistics (http://www.amstat.org/publications/jcgs.cfm
Factors That Influence Radioactive Iodine Use for Thyroid Cancer
Background: There is variation in the use of radioactive iodine (RAI) as treatment for well-differentiated thyroid cancer. The factors involved in physician decision-making for RAI remain unknown. Methods: We surveyed physicians involved in postsurgical management of patients with thyroid cancer from 251 hospitals. Respondents were asked to rate the factors important in influencing whether a thyroid cancer patient receives RAI. Multivariable analyses controlling for physician age, gender, specialty, case volume, and whether they personally administer RAI, were performed to determine correlates of importance placed on patients' and physicians' worry about death from cancer and differences between low? versus higher?case-volume physicians. Results: The survey response rate was 63% (534/853). Extent of disease, adequacy of surgical resection, patients' willingness to receive RAI, and patients' age were the factors physicians were most likely to report as quite or very important in influencing recommendations for RAI to patients with thyroid cancer. Interestingly, both physicians' and patients' worry about death from thyroid cancer were also important in determining RAI use. Physicians with less thyroid cancer cases per year were more likely than higher-volume physicians to report patients' (p<0.001) and physicians' worry about death (p=0.016) as quite or very important in decision-making. Other factors more likely to be of greater importance in determining RAI use for physicians with lower thyroid cancer patient volume versus higher include the accepted standard at the affiliated hospital (p=0.020), beliefs about RAI expressed by colleagues comanaging patients (p=0.003), and patient distance from the nearest facility administering RAI (p=0.012). Conclusion: In addition to the extent of disease and adequacy of surgical resection, physicians place importance on physician and patient worry about death from thyroid cancer when deciding whether to treat a patient with RAI. The factors important to physician decision-making differ based on physician thyroid-cancer case-volume, with worry about death being more influential for low?case-volume physicians. As the mortality from thyroid cancer is low, the importance placed on death in decision making may be unwarranted.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140258/1/thy.2012.0380.pd
Practical Dosimetry of 131I in Patients with Thyroid Carcinoma
Radioiodine treatments of patients with well-differentiated thyroid carcinoma have generally been safe and beneficial. Safety can be ensured while efficacy is increased through practical methods of dosimetry that measure body retention of 131I. Prescriptions for therapeutic 131I can be decreased when the retention level is high and increased when the level is low. Assays of serum free T4 will alert the physician to possible increased radiation to blood and bone marrow, and appreciable concentrations of free T4 are indications to reduce the therapeutic 131I. Carcinomas ≥1 cm in diameter that are not visible on diagnostic scintigraphy are unlikely to respond to the commonly prescribed mCi of 131I. Biologic responses to commonly prescribed levels of therapeutic 131I, as seen in toxic changes of normal tissues and in indices of tumor size, will be the final dosimeters. With lower levels of prescribed diagnostic 131I, stunning should not impair dosimetry. Thus, readily obtained measurements make dosimetry a practical method for improving carcinoma therapy with 131I.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63166/1/10849780252824118.pd
Current Trends in Functional Imaging of Pheochromocytomas and Paragangliomas
Most pheochromocytomas/paragangliomas should be evaluated with anatomical imaging (computed tomography or magnetic resonance imaging) followed by functional imaging (nuclear medicine modalities). Functional imaging assures that the tumor is indeed a pheochromocytoma/paraganglioma and enables more thorough localization, especially detecting as many lesions as possible (in particular for metastatic disease). Functional imaging for pheochromocytomas/paragangliomas, can use radiolabled ligands specific for pathways of synthesis, metabolism, and inactivation of catecholamines or nonspecific ligands. In an overview of the available nuclear medicine modalities, we summarize the accumulated experience and recommend when functional imaging should be applied to patients with pheochromocytoma/paraganglioma.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74881/1/annals.1353.041.pd
Three Dimensional Hydrodynamic Modeling Study, Craney Island eastward expansion, lower James River and Elizabeth River, Virginia
The Craney Island Eastward Expansion Hydrodynamic Model Study was conducted in three phases: 1) model calibration and verification for the Elizabeth River, 2) model testing of four Craney Island expansion options using single variable runs (using a single variable, tidal range, for model input), 3) model testing of two expansion options using historical runs (using multiple variables in real time for model input). The expansion option designs were evaluated for both global and local hydrodynamic change through simulation comparisons with the Base Case condition
Discovery of the Ultra-Bright Type II-L Supernova 2008es
We report the discovery by the Robotic Optical Transient Experiment
(ROTSE-IIIb) telescope of SN 2008es, an overluminous supernova (SN) at z=0.205
with a peak visual magnitude of -22.2. We present multiwavelength follow-up
observations with the Swift satellite and several ground-based optical
telescopes. The ROTSE-IIIb observations constrain the time of explosion to be
23+/-1 rest-frame days before maximum. The linear decay of the optical light
curve, and the combination of a symmetric, broad H\alpha emission line profile
with broad P Cygni H\beta and Na I \lambda5892 profiles, are properties
reminiscent of the bright Type II-L SNe 1979C and 1980K, although SN 2008es is
greater than 10 times more luminous. The host galaxy is undetected in
pre-supernova Sloan Digital Sky Survey images, and similar to Type II-L SN
2005ap (the most luminous SN ever observed), the host is most likely a dwarf
galaxy with M_r > -17. Swift Ultraviolet/Optical Telescope observations in
combination with Palomar photometry measure the SED of the SN from 200 to 800
nm to be a blackbody that cools from a temperature of 14,000 K at the time of
the optical peak to 6400 K 65 days later. The inferred blackbody radius is in
good agreement with the radius expected for the expansion speed measured from
the broad lines (10,000 km/s). The bolometric luminosity at the optical peak is
2.8 x 10^44 erg/s, with a total energy radiated over the next 65 days of 5.6 x
10^50 erg. We favor a model in which the exceptional peak luminosity is a
consequence of the core-collapse explosion of a progenitor star with a low-mass
extended hydrogen envelope and a stellar wind with a density close to the upper
limit on the mass-loss rate measured from the lack of an X-ray detection by the
Swift X-Ray Telescope. (Abridged).Comment: Accepted to ApJ, 14 pages, 7 figures, 3 tables, emulateapj,
corrections from proofs adde
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