787 research outputs found

    Incidentally found rib hemangioma: Case report and discussion of management

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    Rib hemangioma is a rare chest wall tumor for which few reports in the literature exist to help guide treatment. The clinical presentation, radiographic findings, and treatment strategies vary in the literature, with the majority of patients undergoing surgical resection to definitively rule out malignancy. Here, we report a 23-year-old woman with an incidentally discovered rib hemangioma, who had a history of migraines, during the workup of a severe headache refractory to medical treatment. Imaging revealed a solitary, expansile tumor arising from the posterior left third rib. Spinal magnetic resonance imaging (MRI) showed a fat-containing lesion with multiple vascular flow voids, non-enhancement, and high signal intensity on the T2-weighted series. It appeared to have a honeycomb core on chest computed tomography (CT). Imaging characteristics of the lesion were consistent with an intraosseous hemangioma. The tumor was managed with upfront surgical resection without a preoperative biopsy. The case was uneventful and no complications were encountered. The patient recovered well, denied any symptoms four weeks after surgery, and a follow-up chest X-ray was unremarkable. Following resection, the pathological diagnosis was concordant with the radiographic diagnosis of a rib hemangioma. Here, we review existing literature on the rare case of a rib hemangioma with a focus on the radiographic characteristics and management. Given that radiographic features of this lesion were consistent with prior reports and surgery did not change the diagnosis, we suggest that non-operative management be considered for similar lesions, as surgical resection does not appear to reveal occult malignancy in the majority of cases

    A 20-year multicenter analysis of dialysis-dependent patients who had aortic or mitral valve replacement: Implications for valve selection

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    Objective Valve selection in dialysis-dependent patients can be difficult because long-term survival is diminished and bleeding risks during anticoagulation treatment are greater in patients with renal failure. In this study we analyzed long-term outcomes of dialysis-dependent patients who underwent valve replacement to help guide optimal prosthetic valve type selection. Methods Dialysis-dependent patients who underwent aortic and/or mitral valve replacement at 3 institutions over 20 years were examined. The primary outcome was long-term survival. A Cox regression model was used to estimate survival according to 5 ages, presence of diabetes, and/or heart failure symptoms. Results Four hundred twenty-three available patients were analyzed; 341 patients had biological and 82 had mechanical valves. Overall complication and 30-day mortality rates were similar between the groups. Thirty-day readmission rates for biological and mechanical groups were 15% (50/341) and 28% (23/82; P = .005). Five-year survival was 23% and 33% for the biological and mechanical groups, respectively. After adjusting for age, New York Heart Association (NYHA) class, and diabetes using a multivariable Cox regression model, survival was similar between groups (hazard ratio, 0.93; 95% confidence interval, 0.66-1.29; P = .8). A Cox regression model on the basis of age, diabetes, and heart failure, estimated that patients only 30 or 40 years old, with NYHA class I-II failure without diabetes had a >50% estimated 5-year survival (P < .001). Conclusions Dialysis-dependent patients who underwent valve replacement surgery had poor long-term survival. Young patients without diabetes or NYHA III or IV symptoms might survive long enough to justify placement of a mechanical valve; however, a biological valve is suitable for most patients

    Economic evaluation of the specialized donor care facility for thoracic organ donor management

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    Background: Over the last decade two alternative models of donor care have emerged in the United States: the conventional model, whereby donors are managed at the hospital where brain death occurs, and the specialized donor care facility (SDCF), in which brain dead donors are transferred to a SDCF for medical optimization and organ procurement. Despite increasing use of the SDCF model, its cost-effectiveness in comparison to the conventional model remains unknown. Methods: We performed an economic evaluation of the SDCF and conventional model of donor care from the perspective of U.S. transplant centers over a 2-year study period. In this analysis, we utilized nationwide data from the Scientific Registry of Transplant Recipients and controlled for donor characteristics and patterns of organ sharing across the nation\u27s organ procurement organizations (OPOs). Subgroup analysis was performed to determine the impact of the SDCF model on thoracic organ transplants. Results: A total of 38,944 organ transplants were performed in the U.S. during the study period from 13,539 donors with an observed total organ cost of 1.36billion.IfeveryOPOassumedthecostandeffectivenessoftheSDCFmodel,apredicted39,155organtransplants(+211)wouldhavebeenperformedwithapredictedtotalorgancostof1.36 billion. If every OPO assumed the cost and effectiveness of the SDCF model, a predicted 39,155 organ transplants (+211) would have been performed with a predicted total organ cost of 1.26 billion (-100million).SubgroupanalysisofthoracicorgansrevealedthattheSDCFmodelwouldleadtoapredicted156additionaltransplantswithacostsavingof100 million). Subgroup analysis of thoracic organs revealed that the SDCF model would lead to a predicted 156 additional transplants with a cost saving of 24.6 million. Conclusions: The U.S. SDCF model may be a less costly and more effective means of multi-organ donor management, particularly for thoracic organ donors, compared to the conventional hospital-based model

    Kepler Planet-Detection Mission: Introduction and First Results

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    The Kepler mission was designed to determine the frequency of Earth-sized planets in and near the habitable zone of Sun-like stars. The habitable zone is the region where planetary temperatures are suitable for water to exist on a planet’s surface. During the first 6 weeks of observations, Kepler monitored 156,000 stars, and five new exoplanets with sizes between 0.37 and 1.6 Jupiter radii and orbital periods from 3.2 to 4.9 days were discovered. The density of the Neptune-sized Kepler-4b is similar to that of Neptune and GJ 436b, even though the irradiation level is 800,000 times higher. Kepler-7b is one of the lowest-density planets (~0.17 gram per cubic centimeter) yet detected. Kepler-5b, -6b, and -8b confirm the existence of planets with densities lower than those predicted for gas giant planets

    Millipede taxonomy after 250 years: classification and taxonomic practices in a mega-diverse yet understudied arthropod group.

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    BACKGROUND: The arthropod class Diplopoda is a mega-diverse group comprising >12,000 described millipede species. The history of taxonomic research within the group is tumultuous and, consequently, has yielded a questionable higher-level classification. Few higher-taxa are defined using synapomorphies, and the practice of single taxon descriptions lacking a revisionary framework has produced many monotypic taxa. Additionally, taxonomic and geographic biases render global species diversity estimations unreliable. We test whether the ordinal taxa of the Diplopoda are consistent with regards to underlying taxonomic diversity, attempt to provide estimates for global species diversity, and examine millipede taxonomic effort at a global geographic scale. METHODOLOGY/PRINCIPAL FINDINGS: A taxonomic distinctness metric was employed to assess uniformity of millipede ordinal taxa. We found that ordinal-level taxa are not uniform and are likely overinflated with higher-taxa when compared to related groups. Several methods of estimating global species richness were employed (Bayesian, variation in taxonomic productivity, extrapolation from nearly fully described taxa). Two of the three methods provided estimates ranging from 13,413-16,760 species. Variations in geographic diversity show biases to North America and Europe and a paucity of works on tropical taxa. CONCLUSIONS/SIGNIFICANCE: Before taxa can be used in an extensible way, they must be definable with respect to the diversity they contain and the diagnostic characters used to delineate them. The higher classification for millipedes is shown to be problematic from a number of perspectives. Namely, the ordinal taxa are not uniform in their underlying diversity, and millipedes appear to have a disproportionate number of higher-taxa. Species diversity estimates are unreliable due to inconsistent taxonomic effort at temporal, geographic, and phylogenetic scales. Lack of knowledge concerning many millipede groups compounds these issues. Diplopods are likely not unique in this regard as these issues may persist in many other diverse yet poorly studied groups

    The functional loss of the retinoblastoma tumour suppressor is a common event in basal-like and luminal B breast carcinomas

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    Introduction Breast cancers can be classified using whole genome expression into distinct subtypes that show differences in prognosis. One of these groups, the basal-like subtype, is poorly differentiated, highly metastatic, genomically unstable, and contains specific genetic alterations such as the loss of tumour protein 53 (TP53). The loss of the retinoblastoma tumour suppressor encoded by the RB1 locus is a well-characterised occurrence in many tumour types; however, its role in breast cancer is less clear with many reports demonstrating a loss of heterozygosity that does not correlate with a loss of RB1 protein expression. Methods We used gene expression analysis for tumour subtyping and polymorphic markers located at the RB1 locus to assess the frequency of loss of heterozygosity in 88 primary human breast carcinomas and their normal tissue genomic DNA samples. Results RB1 loss of heterozygosity was observed at an overall frequency of 39%, with a high frequency in basal-like (72%) and luminal B (62%) tumours. These tumours also concurrently showed low expression of RB1 mRNA. p16INK4a was highly expressed in basal-like tumours, presumably due to a previously reported feedback loop caused by RB1 loss. An RB1 loss of heterozygosity signature was developed and shown to be highly prognostic, and was potentially a predictive marker of response to neoadjuvant chemotherapy. Conclusions These results suggest that the functional loss of RB1 is common in basal-like tumours, which may play a key role in dictating their aggressive biology and unique therapeutic responses

    Amyloid-related imaging abnormalities in the DIAN-TU-001 trial of gantenerumab and solanezumab: lessons from a trial in dominantly inherited Alzheimer disease

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    OBJECTIVE: To determine the characteristics of participants with amyloid-related imaging abnormalities (ARIA) in a trial of gantenerumab or solanezumab in dominantly inherited Alzheimer disease (DIAD). METHODS: 142 DIAD mutation carriers received either gantenerumab SC (n=52), solanezumab IV (n=50), or placebo (n=40). Participants underwent assessments with the Clinical Dementia Rating® (CDR®), neuropsychological testing, CSF biomarkers, β-amyloid positron emission tomography (PET), and magnetic resonance imaging (MRI) to monitor ARIA. Cross-sectional and longitudinal analyses evaluated potential ARIA-related risk factors. RESULTS: Eleven participants developed ARIA-E, including 3 with mild symptoms. No ARIA-E was reported under solanezumab while gantenerumab was associated with ARIA-E compared to placebo (OR=9.1, CI[1.2, 412.3]; p=0.021). Under gantenerumab, APOE-ɛ4 carriers were more likely to develop ARIA-E (OR=5.0, CI[1.0, 30.4]; p=0.055), as were individuals with microhemorrhage at baseline (OR=13.7, CI[1.2, 163.2]; p=0.039). No ARIA-E was observed at the initial 225mg/month gantenerumab dose, and most cases were observed at doses >675mg. At first ARIA-E occurrence, all ARIA-E participants were amyloid-PET+, 60% were CDR>0, 60% were past their estimated year to symptom onset, and 60% had also incident ARIA-H. Most ARIA-E radiologically resolved after dose adjustment and developing ARIA-E did not significantly increase odds of trial discontinuation. ARIA-E was more frequently observed in the occipital lobe (90%). ARIA-E severity was associated with age at time of ARIA-E. INTERPRETATION: In DIAD, solanezumab was not associated with ARIA. Gantenerumab dose over 225mg increased ARIA-E risk, with additional risk for individuals APOE-ɛ4(+) or with microhemorrhage. ARIA-E was reversible on MRI in most cases, generally asymptomatic, without additional risk for trial discontinuation. This article is protected by copyright. All rights reserved
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