187 research outputs found

    Diagnostic examination of the child with urolithiasis or nephrocalcinosis

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    Urolithiasis and nephrocalcinosis are more frequent in children then currently anticipated, but still remain under- or misdiagnosed in a significant proportion of patients, since symptoms and signs may be subtle or misleading. All children with colicky abdominal pain or macroscopic hematuria should be examined thoroughly for urolithiasis. Also, other, more general, abdominal manifestations can be the first symptoms of renal stones. The patients and their family histories, as well as physical examination, are important initial steps for diagnostic evaluation. Thereafter, diagnostic imaging should be aimed at the location of calculi but also at identification of urinary tract anomalies or acute obstruction due to stone disease. This can often be accomplished by ultrasound examination alone, but sometimes radiological methods such as plain abdominal films or more sensitive non-enhanced computed tomography are necessary. Since metabolic causes are frequent in children, diagnostic evaluation should be meticulous so that metabolic disorders that cause recurrent urolithiasis or even renal failure, such as the primary hyperoxalurias and others, can be ruled out. The stone is not the disease itself; it is only one serious sign! Therefore, thorough and early diagnostic examination is mandatory for every infant and child with the first stone event, or with nephrocalcinosis

    Definitive and adjuvant radiotherapy for sinonasal squamous cell carcinomas: a single institutional experience

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    Background: The aim of this study was to evaluate the disease outcomes of patients treated with definitive and adjuvant radiotherapy for squamous cell carcinomas of the nasal cavity and paranasal sinuses in a single institution. Methods: Between 2007–2012 patients were retrospectively identified from electronic databases who had undergone surgery and adjuvant radiotherapy or definitive radiotherapy for sinonasal squamous cell carcinomas with curative intent. Results: Fourty three patients with sinonasal squamous cell carcinoma were identified (22 nasal cavity, 21 paranasal sinuses). 31/43 (72 %) had T3 or T4 disease; nodal stage was N0 in 38, N1 in 4, Na/b in 0 and N2c in 1 patient. Median age was 67 years (range 41–86). 18 (42 %) received definitive and 25 (58 %) adjuvant radiotherapy. Radiotherapy was delivered using either conventional radiotherapy (n = 39) or intensity modulated radiotherapy (n = 4). Elective neck radiotherapy was delivered to two patients. Chemotherapy was delivered to 6/43 (14 %) of patients. Two-year local control, regional control, distant metastases free survival, progression free survival, cause specific survival and overall survival were 81 %, 90 %, 95 %, 71 %, 84 % and 80 % respectively. There was no significant difference in outcome comparing patients who underwent surgery and adjuvant radiotherapy with patients receiving definitive radiotherapy (2 year locoregional disease free survival 75 % and 70 % respectively, p = 0.98). Pooly differentiated tumours were significantly associated with inferior disease outcomes. Local, regional, combined local and regional, and distant failure occurred in 7 (16 %), 3 (7 %), 1 (2 %) and 2 (5 %) of patients; all 3 regional recurrences were in patients with nasal cavity squamous cell carcinomas who had not undergone elective neck treatment. Conclusions: Definitive or adjuvant radiotherapy provides an effective treatment for sinonasal malignancies. The main pattern of failure remains local, suggesting the need for investigation of intensified local therapy. Whilst remaining uncommon, the cases of regional failure mean that the merits of elective lymph node treatment should be considered on an individual basis

    Predicted risks of radiogenic cardiac toxicity in two pediatric patients undergoing photon or proton radiotherapy

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    BACKGROUND: Hodgkin disease (HD) and medulloblastoma (MB) are common malignancies found in children and young adults, and radiotherapy is part of the standard treatment. It was reported that these patients who received radiation therapy have an increased risk of cardiovascular late effects. We compared the predicted risk of developing radiogenic cardiac toxicity after photon versus proton radiotherapies for a pediatric patient with HD and a pediatric patient with MB. METHODS: In the treatment plans, each patient’s heart was contoured in fine detail, including substructures of the pericardium and myocardium. Risk calculations took into account both therapeutic and stray radiation doses. We calculated the relative risk (RR) of cardiac toxicity using a linear risk model and the normal tissue complication probability (NTCP) values using relative seriality and Lyman models. Uncertainty analyses were also performed. RESULTS: The RR values of cardiac toxicity for the HD patient were 7.27 (proton) and 8.37 (photon), respectively; the RR values for the MB patient were 1.28 (proton) and 8.39 (photon), respectively. The predicted NTCP values for the HD patient were 2.17% (proton) and 2.67% (photon) for the myocardium, and were 2.11% (proton) and 1.92% (photon) for the whole heart. The predicted ratios of NTCP values (proton/photon) for the MB patient were much less than unity. Uncertainty analyses revealed that the predicted ratio of risk between proton and photon therapies was sensitive to uncertainties in the NTCP model parameters and the mean radiation weighting factor for neutrons, but was not sensitive to heart structure contours. The qualitative findings of the study were not sensitive to uncertainties in these factors. CONCLUSIONS: We conclude that proton and photon radiotherapies confer similar predicted risks of cardiac toxicity for the HD patient in this study, and that proton therapy reduced the predicted risk for the MB patient in this study

    Molecular Etiology of Atherogenesis – In Vitro Induction of Lipidosis in Macrophages with a New LDL Model

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    BACKGROUND: Atherosclerosis starts by lipid accumulation in the arterial intima and progresses into a chronic vascular inflammatory disease. A major atherogenic process is the formation of lipid-loaded macrophages in which a breakdown of the endolysomal pathway results in irreversible accumulation of cargo in the late endocytic compartments with a phenotype similar to several forms of lipidosis. Macrophages exposed to oxidized LDL exihibit this phenomenon in vitro and manifest an impaired degradation of internalized lipids and enhanced inflammatory stimulation. Identification of the specific chemical component(s) causing this phenotype has been elusive because of the chemical complexity of oxidized LDL. METHODOLOGY/PRINCIPAL FINDINGS: Lipid "core aldehydes" are formed in oxidized LDL and exist in atherosclerotic plaques. These aldehydes are slowly oxidized in situ and (much faster) by intracellular aldehyde oxidizing systems to cholesteryl hemiesters. We show that a single cholesteryl hemiester incorporated into native, non-oxidized LDL induces a lipidosis phenotype with subsequent cell death in macrophages. Internalization of the cholesteryl hemiester via the native LDL vehicle induced lipid accumulation in a time- and concentration-dependent manner in "frozen" endolysosomes. Quantitative shotgun lipidomics analysis showed that internalized lipid in cholesteryl hemiester-intoxicated cells remained largely unprocessed in those lipid-rich organelles. CONCLUSIONS/SIGNIFICANCE: The principle elucidated with the present cholesteryl hemiester-containing native-LDL model, extended to other molecular components of oxidized LDL, will help in defining the molecular etiology and etiological hierarchy of atherogenic agents

    Proctitis following stereotactic body radiation therapy for prostate cancer

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    Background Proctitis after radiation therapy for prostate cancer remains an ongoing clinical challenge and critical quality of life issue. SBRT could minimize rectal toxicity by reducing the volume of rectum receiving high radiation doses and offers the potential radiobiologic benefits of hypofractionation. This study sought to evaluate the incidence and severity of proctitis following SBRT for prostate cancer. Methods Between February 2008 and July 2011, 269 men with clinically localized prostate cancer were treated definitively with SBRT monotherapy at Georgetown University Hospital. All patients were treated to 35-36.25Gy in 5 fractions delivered with the CyberKnife Radiosurgical System (Accuray). Rectal bleeding was recorded and scored using the CTCAE v.4. Telangiectasias were graded using the Vienna Rectoscopy Score (VRS). Proctitis was assessed via the Bowel domain of the Expanded Prostate Index Composite (EPIC)-26 at baseline and at 1, 3, 6, 9, 12, 18 and 24 months post-SBRT. Results The median age was 69 years with a median prostate volume of 39 cc. The median follow-up was 3.9 years with a minimum follow-up of two years. The 2-year actuarial incidence of late rectal bleeding ≥ grade 2 was 1.5%. Endoscopy revealed VRS Grade 2 rectal telangiectasias in 11% of patients. All proctitis symptoms increased at one month post-SBRT but returned to near-baseline with longer follow-up. The most bothersome symptoms were bowel urgency and frequency. At one month post-SBRT, 11.2% and 8.5% of patients reported a moderate to big problem with bowel urgency and frequency, respectively. The EPIC bowel summary scores declined transiently at 1 month and experienced a second, more protracted decline between 6 months and 18 months before returning to near-baseline at two years post-SBRT. Prior to treatment, 4.1% of men felt their bowel function was a moderate to big problem which increased to 11.5% one month post-SBRT but returned to near-baseline at two years post-SBRT. Conclusions In this single institution cohort, the rate and severity of proctitis observed following SBRT is low. QOL decreased on follow-up; however, our results compare favorably to those reported for patients treated with alternative radiation modalities. Future prospective randomized studies are needed to confirm these observations

    Binary systems and their nuclear explosions

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    Peer ReviewedPreprin

    Developmental malformation of the corpus callosum: a review of typical callosal development and examples of developmental disorders with callosal involvement

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    This review provides an overview of the involvement of the corpus callosum (CC) in a variety of developmental disorders that are currently defined exclusively by genetics, developmental insult, and/or behavior. I begin with a general review of CC development, connectivity, and function, followed by discussion of the research methods typically utilized to study the callosum. The bulk of the review concentrates on specific developmental disorders, beginning with agenesis of the corpus callosum (AgCC)—the only condition diagnosed exclusively by callosal anatomy. This is followed by a review of several genetic disorders that commonly result in social impairments and/or psychopathology similar to AgCC (neurofibromatosis-1, Turner syndrome, 22q11.2 deletion syndrome, Williams yndrome, and fragile X) and two forms of prenatal injury (premature birth, fetal alcohol syndrome) known to impact callosal development. Finally, I examine callosal involvement in several common developmental disorders defined exclusively by behavioral patterns (developmental language delay, dyslexia, attention-deficit hyperactive disorder, autism spectrum disorders, and Tourette syndrome)

    Lawson criterion for ignition exceeded in an inertial fusion experiment

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    For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion
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