694 research outputs found
Diagnostic and therapeutic dilemmas in intra-abdominal desmoid tumors: A case report and literature review
AbstractIntroductionIntra-abdominal desmoid tumors (DTs) are a rare and anatomically diverse group of locally-aggressive, benign neoplasms. They are often difficult to diagnose, even in patients who possess risk factors for the disease. Even after a diagnosis has been reached, the optimal therapy is often not well-defined.Presentation of caseThe case discussed of a 33-year old male with a giant intra-abdominal desmoid is an example of both the diagnostic and therapeutic dilemmas that arise when confronted with a patient with a DT. Initial confusion over diagnosis led to ineffective therapy, but once the correct diagnosis was made, the patient went on to definitive surgical resection.DiscussionThe differential diagnosis of DTs is broad, and the diagnosis is often delayed due to nonspecific presentations. Immunohistochemistry is crucial in the accurate histological diagnosis, which guides treatment. Chemotherapy and radiation have a role in the management of both primary and recurrent lesions, but surgical resection remains the cornerstone of treatment.ConclusionDTs present a clinical challenge in their diagnosis and management, and despite providing standard medical and surgical treatment, recurrence rates are high and continued surveillance is crucial
Successful Instructional Reading Practices for African American Male Third-Grade Students
African American male third graders in U.S Title I schools frequently fail to read on grade level. However, in three Title I schools in East Texas, this demographic demonstrated exceptionally high reading ability. This explanatory case study investigated the instructional strategies and practices linked to high reading achievement for these students. The study is grounded in Ladson-Billings’s theory of culturally relevant pedagogy and supported by Vygotsky’s theory of social and cognitive constructivism. The research questions were used to examine the instructional strategies and practices used on each campus that may have resulted in such high reading achievement. This study engenders a deeper understanding of effective instructional reading strategies and practices for African American boys at the elementary level
Communicating nanoscience and the communication center: An INNOVATE case study
Communication Centers are well positioned to support communicating science efforts across campus. This manuscript, written by faculty who designed and facilitated a potpourri of support for nanoscience during the 2017-18 academic year, provides a detailed place to start for those who will take on this work at other institutions
Multimodal Imaging of Photoreceptor Structure in Choroideremia
Purpose
Choroideremia is a progressive X-linked recessive dystrophy, characterized by degeneration of the retinal pigment epithelium (RPE), choroid, choriocapillaris, and photoreceptors. We examined photoreceptor structure in a series of subjects with choroideremia with particular attention to areas bordering atrophic lesions. Methods
Twelve males with clinically-diagnosed choroideremia and confirmed hemizygous mutations in the CHM gene were examined. High-resolution images of the retina were obtained using spectral domain optical coherence tomography (SD-OCT) and both confocal and non-confocal split-detector adaptive optics scanning light ophthalmoscope (AOSLO) techniques. Results
Eleven CHM gene mutations (3 novel) were identified; three subjects had the same mutation and one subject had two mutations. SD-OCT findings included interdigitation zone (IZ) attenuation or loss in 10/12 subjects, often in areas with intact ellipsoid zones; RPE thinning in all subjects; interlaminar bridges in the imaged areas of 10/12 subjects; and outer retinal tubulations (ORTs) in 10/12 subjects. Only split-detector AOSLO could reliably resolve cones near lesion borders, and such cones were abnormally heterogeneous in morphology, diameter and density. On split-detector imaging, the cone mosaic terminated sharply at lesion borders in 5/5 cases examined. Split-detector imaging detected remnant cone inner segments within ORTs, which were generally contiguous with a central patch of preserved retina. Conclusions
Early IZ dropout and RPE thinning on SD-OCT are consistent with previously published results. Evidence of remnant cone inner segments within ORTs and the continuity of the ORTs with preserved retina suggests that these may represent an intermediate state of retinal degeneration prior to complete atrophy. Taken together, these results supports a model of choroideremia in which the RPE degenerates before photoreceptors
Misalignments: Challenges in Cultivating Science Faculty with Education Specialties in Your Department
Science Faculty with Education Specialties (SFES) are increasingly being hired across the United States. However, little is known about the motivations for SFES hiring or the potential or actual impact of SFES. In the context of a recent national survey of US SFES, we investigated SFES perceptions about these issues. Strikingly, perceptions about reasons for hiring SFES were poorly aligned with perceptions about potential and actual contributions reported by SFES themselves, and the advice they extended to beginning SFES was varied. While preparation of future teachers and departmental teaching needs were common reasons offered for SFES hiring, the potential and actual contributions of SFES highlighted instead their roles as pedagogical resources and as contributors to curricular reform. Misalignments between SFES perceptions about what motivates SFES hiring and their perceptions of their most valuable contributions present challenges for those interested in maximizing the impact of SFES
Self-consistent theory of reversible ligand binding to a spherical cell
In this article, we study the kinetics of reversible ligand binding to
receptors on a spherical cell surface using a self-consistent stochastic
theory. Binding, dissociation, diffusion and rebinding of ligands are
incorporated into the theory in a systematic manner. We derive explicitly the
time evolution of the ligand-bound receptor fraction p(t) in various regimes .
Contrary to the commonly accepted view, we find that the well-known
Berg-Purcell scaling for the association rate is modified as a function of
time. Specifically, the effective on-rate changes non-monotonically as a
function of time and equals the intrinsic rate at very early as well as late
times, while being approximately equal to the Berg-Purcell value at
intermediate times. The effective dissociation rate, as it appears in the
binding curve or measured in a dissociation experiment, is strongly modified by
rebinding events and assumes the Berg-Purcell value except at very late times,
where the decay is algebraic and not exponential. In equilibrium, the ligand
concentration everywhere in the solution is the same and equals its spatial
mean, thus ensuring that there is no depletion in the vicinity of the cell.
Implications of our results for binding experiments and numerical simulations
of ligand-receptor systems are also discussed.Comment: 23 pages with 4 figure
Landscape Genetics Reveals Focal Transmission of a Human Macroparasite
Macroparasite infections (e.g., helminths) remain a major human health concern. However, assessing transmission dynamics is problematic because the direct observation of macroparasite dispersal among hosts is not possible. We used a novel landscape genetics approach to examine transmission of the human roundworm Ascaris lumbricoides in a small human population in Jiri, Nepal. Unexpectedly, we found significant genetic structuring of parasites, indicating the presence of multiple transmission foci within a small sampling area (∼14 km2). We analyzed several epidemiological variables, and found that transmission is spatially autocorrelated around households and that transmission foci are stable over time despite extensive human movement. These results would not have been obtainable via a traditional epidemiological study based on worm counts alone. Our data refute the assumption that a single host population corresponds to a single parasite transmission unit, an assumption implicit in many classic models of macroparasite transmission. Newer models have shown that the metapopulation-like pattern observed in our data can adversely affect targeted control strategies aimed at community-wide impacts. Furthermore, the observed metapopulation structure and local mating patterns generate an excess of homozygotes that can accelerate the spread of recessive traits such as drug resistance. Our study illustrates how molecular analyses complement traditional epidemiological information in providing a better understanding of parasite transmission. Similar landscape genetic approaches in other macroparasite systems will be warranted if an accurate depiction of the transmission process is to be used to inform effective control strategies
Reality Versus Grant Application Research “Plans”
This article describes the implementation of the American Indian mHealth Smoking Dependence Study focusing on the differences between what was written in the grant application compared to what happened in reality. The study was designed to evaluate a multicomponent intervention involving 256 participants randomly assigned to one of 15 groups. Participants received either a minimal or an intense level of four intervention components: (1) nicotine replacement therapy, (2) precessation counseling, (3) cessation counseling, and (4) mHealth text messaging. The project team met via biweekly webinars as well as one to two in-person meetings per year throughout the study. The project team openly shared progress and challenges and collaborated to find proactive solutions to address challenges as compared to what was planned in the original grant application. The project team used multiple strategies to overcome unanticipated intervention issues: (1) cell phone challenges, (2) making difficult staffing decisions, (3) survey lessons, (4) nicotine replacement therapy, (5) mHealth text messages, (6) motivational interviewing counseling sessions, and (7) use of e-cigarettes. Smoking cessation studies should be designed based on the grant plans. However, on the ground reality issues needed to be addressed to assure the scientific rigor and innovativeness of this study
Host genetics and population structure effects on parasitic disease
Host genetic factors exert significant influences on differential susceptibility to many infectious diseases. In addition, population structure of both host and parasite may influence disease distribution patterns. In this study, we assess the effects of population structure on infectious disease in two populations in which host genetic factors influencing susceptibility to parasitic disease have been extensively studied. The first population is the Jirel population of eastern Nepal that has been the subject of research on the determinants of differential susceptibility to soil-transmitted helminth infections. The second group is a Brazilian population residing in an area endemic for Trypanosoma cruzi infection that has been assessed for genetic influences on differential disease progression in Chagas disease. For measures of Ascaris worm burden, within-population host genetic effects are generally more important than host population structure factors in determining patterns of infectious disease. No significant influences of population structure on measures associated with progression of cardiac disease in individuals who were seropositive for T. cruzi infection were found
COVID-19 in hospitalized adult patients with sickle cell disease: A 2020 United States cohort using Cerner Real-World Data™ (CRWD)
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