44 research outputs found

    Management of Indeterminate Cystic Kidney Lesions: Review of Contrast-enhanced Ultrasound as a Diagnostic Tool

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    Indeterminate cystic kidney lesions found incidentally on abdominal imaging are an increasingly prevalent diagnostic challenge. The standard workup includes Bosniak classification with contrast-enhanced CT or MRI. However, these tests are costly and not without risks. Contrast-enhanced ultrasound (CEUS) is a relatively new imaging technique with lower risk of adverse events than iodine-containing contrast or gadolinium. In our review of the evidence for characterization of cystic kidney lesions with CEUS, CEUS displayed sensitivity (89–100%) and negative predictive value (86–100%) comparable to contrast-enhanced CT or MRI with no decrease in specificity compared to CT and only a slight decrease compared to MRI

    A Pilot Clinical Study in Characterization of Malignant Renal-cell Carcinoma Subtype with Contrast-enhanced Ultrasound

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    Malignant renal cell carcinoma (RCC) is a diverse set of diseases, which are independently difficult to characterize using conventional MRI and CT protocols due to low temporal resolution to study perfusion characteristics. Because different disease subtypes have different prognoses and involve varying treatment regimens, the ability to determine RCC subtype non-invasively is a clinical need. Contrast-enhanced ultrasound (CEUS) has been assessed as a tool to characterize kidney lesions based on qualitative and quantitative assessment of perfusion patterns, and we hypothesize that this technique might help differentiate disease subtypes. Twelve patients with RCC confirmed pathologically were imaged using contrast-enhanced ultrasound. Time intensity curves were generated and analyzed quantitatively using ten characteristic metrics. Results showed that peak intensity (p=0.001) and time-to-80% on wash-out (p=0.004) provided significant differences between clear cell, papillary, and chromophobe RCC subtypes. These results suggest that CEUS may be a feasible test for characterizing RCC subtypes

    Diagnostic accuracy of contrast-enhanced ultrasound for characterization of kidney lesions in patients with and without chronic kidney disease

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    Abstract Background Patients with chronic kidney disease are at increased risk of cystic kidney disease that requires imaging monitoring in many cases. However, these same patients often have contraindications to contrast-enhanced computed tomography and magnetic resonance imaging. This study evaluates the accuracy of contrast-enhanced ultrasound (CEUS), which is safe for patients with chronic kidney disease, for the characterization of kidney lesions in patients with and without chronic kidney disease. Methods We performed CEUS on 44 patients, both with and without chronic kidney disease, with indeterminate or suspicious kidney lesions (both cystic and solid). Two masked radiologists categorized lesions using CEUS images according to contrast-enhanced ultrasound adapted criteria. CEUS designation was compared to histology or follow-up imaging in cases without available tissue in all patients and the subset with chronic kidney disease to determine sensitivity, specificity and overall accuracy. Results Across all patients, CEUS had a sensitivity of 96% (95% CI: 84%, 99%) and specificity of 50% (95% CI: 32%, 68%) for detecting malignancy. Among patients with chronic kidney disease, CEUS sensitivity was 90% (95% CI: 56%, 98%), and specificity was 55% (95% CI: 36%, 73%). Conclusions CEUS has high sensitivity for identifying malignancy of kidney lesions. However, because specificity is low, modifications to the classification scheme for contrast-enhanced ultrasound could be considered as a way to improve contrast-enhanced ultrasound specificity and thus overall performance. Due to its sensitivity, among patients with chronic kidney disease or other contrast contraindications, CEUS has potential as an imaging test to rule out malignancy. Trial registration This trial was registered in clinicaltrials.gov, NCT01751529

    Intravenous immunoglobulin treatment for encephalitis in children aged 6 months to 16 years: the IgNiTE RCT

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    Background: There are data suggesting that intravenous immunoglobulin treatment has some benefit for certain forms of encephalitis but robust evidence from large randomised controlled trials in children with all-cause encephalitis is lacking. Objective: To evaluate whether intravenous immunoglobulin treatment improves neurological outcomes in childhood encephalitis when given early in the illness. Design: Phase 3b, investigator-initiated, randomised, double-blind, placebo-controlled trial of intravenous immunoglobulin for the treatment of encephalitis in children. Setting: Twenty-one NHS Hospitals in the UK. Participants: Children aged 6 months to 16 years with a diagnosis of acute or sub-acute encephalitis. Intervention: Two doses (1 g/kg/dose) of either intravenous immunoglobulin or matching placebo, given 24–36 hours apart, in addition to standard treatment. Main outcome measure: Participants were followed up for 12 months (+/– 4 weeks) after randomisation. The primary outcome measure was a ‘good recovery’ defined as a score of ≤ 2 on the Paediatric Glasgow Outcome Score Extended at 12 months after randomisation. Secondary outcomes: The secondary outcomes were clinical, neurological, neuroimaging and neuropsychological results, identification of the proportion of children with immune-mediated encephalitis, and intravenous immunoglobulin safety data. Results: We planned to recruit 308 children over a 42-month period. After enrolment of 18 participants (8 male; 44%) over 21 months (from December 2015 to September 2017), funding was withdrawn due to slow recruitment and the study was terminated. Ten participants were randomised to the intravenous immunoglobulin group, and eight to the placebo group, and all 18 participants were included in the analysis. At 12 months after randomisation, 9 participants [50%; intravenous immunoglobulin n = 5 (50%), placebo n = 4 (50%)] made good recovery and 5 participants [28%; intravenous immunoglobulin n = 3 (30%), placebo n = 2 (25%)] made a poor recovery. Three participants in the placebo group (43%) experienced a total of 10 serious adverse events compared with none in the intravenous immunoglobulin group but none of the adverse events were judged to be related to the study treatment. No deaths occurred during the study period. Conclusion: ImmunoglobuliN in the Treatment of Encephalitis (IgNiTE) was halted prematurely due to slow recruitment. Given the small sample size, the study was underpowered to evaluate the effect of intravenous immunoglobulin when compared with placebo in childhood encephalitis. The study findings, albeit from a small sample size, support existing evidence that encephalitis results in poor neurological outcomes for many children. Lessons learned from the ImmunoglobuliN in the Treatment of Encephalitis trial would be valuable for the success of future trials set up to address the efficacy of early treatment with intravenous immunoglobulin in all-cause encephalitis in children. Study limitations and future work: The study was underpowered to evaluate the efficacy of intravenous immunoglobulin in the treatment of childhood encephalitis due to the small sample size achieved. Future trials should seek to address this important question. Trial registration: This trial is registered as Clinical Trials.gov (NCT02308982) and ISRCTN15791925. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation (EME) programme (NIHR award ref: 12/212/15) and is published in full in Efficacy and Mechanism Evaluation; Vol. 11, No. 6. See the NIHR Funding and Awards website for further award information

    Mutations in thyroid hormone receptor α1 cause premature neurogenesis and progenitor cell depletion in human cortical development.

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    Mutations in the thyroid hormone receptor α 1 gene (THRA) have recently been identified as a cause of intellectual deficit in humans. Patients present with structural abnormalities including microencephaly, reduced cerebellar volume and decreased axonal density. Here, we show that directed differentiation of THRA mutant patient-derived induced pluripotent stem cells to forebrain neural progenitors is markedly reduced, but mutant progenitor cells can generate deep and upper cortical layer neurons and form functional neuronal networks. Quantitative lineage tracing shows that THRA mutation-containing progenitor cells exit the cell cycle prematurely, resulting in reduced clonal output. Using a micropatterned chip assay, we find that spatial self-organization of mutation-containing progenitor cells in vitro is impaired, consistent with down-regulated expression of cell-cell adhesion genes. These results reveal that thyroid hormone receptor α1 is required for normal neural progenitor cell proliferation in human cerebral cortical development. They also exemplify quantitative approaches for studying neurodevelopmental disorders using patient-derived cells in vitro.NIHR Cambridge Biomedical Centr

    Mutations in the histone methyltransferase gene KMT2B cause complex early-onset dystonia.

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    Histone lysine methylation, mediated by mixed-lineage leukemia (MLL) proteins, is now known to be critical in the regulation of gene expression, genomic stability, cell cycle and nuclear architecture. Despite MLL proteins being postulated as essential for normal development, little is known about the specific functions of the different MLL lysine methyltransferases. Here we report heterozygous variants in the gene KMT2B (also known as MLL4) in 27 unrelated individuals with a complex progressive childhood-onset dystonia, often associated with a typical facial appearance and characteristic brain magnetic resonance imaging findings. Over time, the majority of affected individuals developed prominent cervical, cranial and laryngeal dystonia. Marked clinical benefit, including the restoration of independent ambulation in some cases, was observed following deep brain stimulation (DBS). These findings highlight a clinically recognizable and potentially treatable form of genetic dystonia, demonstrating the crucial role of KMT2B in the physiological control of voluntary movement.Funding for the project was provided by the Wellcome Trust for UK10K (WT091310) and DDD Study. The DDD study presents independent research commissioned by the Health Innovation Challenge Fund [grant number HICF-1009-003] - see www.ddduk.org/access.html for full acknowledgement. This work was supported in part by the Intramural Research Program of the National Human Genome Research Institute and the Common Fund, NIH Office of the Director. This work was supported in part by the German Ministry of Research and Education (grant nos. 01GS08160 and 01GS08167; German Mental Retardation Network) as part of the National Genome Research Network to A.R. and D.W. and by the Deutsche Forschungsgemeinschaft (AB393/2-2) to A.R. Brain expression data was provided by the UK Human Brain Expression Consortium (UKBEC), which comprises John A. Hardy, Mina Ryten, Michael Weale, Daniah Trabzuni, Adaikalavan Ramasamy, Colin Smith and Robert Walker, affiliated with UCL Institute of Neurology (J.H., M.R., D.T.), King’s College London (M.R., M.W., A.R.) and the University of Edinburgh (C.S., R.W.)

    La inserción de la minería artesanal en la economía familiar campesina : un estudio de caso en la comunidad campesina de Ayahuay (Apurímac)

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    TesisEsta investigación trata sobre la importancia que tiene la minería artesanal en la economía familiar campesina en la comunidad campesina de Ayahuay (Apurímac). A partir de una observación y análisis del uso de tiempo de las familias, se identifica a tres tipos de familias de mineros: mineros constantes, mineros intermitentes (activos y pasivos) y ex mineros. Estas familias no solo se dedican a la minería, sino también a la agricultura, ganadería, trabajos eventuales, comercio, transporte, entre otras actividades, en una lógica de pluriactividad. La prioridad e importancia de cada actividad varía en cada familia de acuerdo a sus objetivos, limitaciones y prioridades. No obstante, podemos distinguir dos grupos de familias: el grupo de familias de mineros contantes y ex mineros transportistas o con empleo, caracterizado por ser menos pluriactivo (más especializado) y con estrategias menos campesinas; y el grupo de familias de mineros intermitentes y ex mineros no transportistas y sin empleo, caracterizado por ser más pluriactivo y con estrategias más campesinas
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