The Experts below are selected from a list of 120 Experts worldwide ranked by ideXlab platform

Alev Kadioglu - One of the best experts on this subject based on the ideXlab platform.

  • renal measurements including length parenchymal thickness and Medullary Pyramid thickness in healthy children what are the normative ultrasound values
    American Journal of Roentgenology, 2010
    Co-Authors: Alev Kadioglu
    Abstract:

    OBJECTIVE. The objective of our study was to develop, by use of ultrasound, nomograms of renal parenchymal thickness, Medullary Pyramid thickness (height), renal length, and the ratio of Medullary Pyramid thickness to parenchymal thickness in healthy children.SUBJECTS AND METHODS. This prospective study included 292 consecutive children (136 boys and 156 girls) who were referred between October 2008 and March 2009 for problems other than urinary tract symptoms or underlying kidney disorders. The children were between 1 month and 18 years old (mean age, 6.1 ± 5.9 years). Real-time gray-scale sonography was performed with a linear or curved array transducer. All examinations were performed by the same experienced radiologist (16 years of experience in pediatric sonography at the time the study began). All the children were well hydrated and had full bladders at the time of examination. Renal length measurements were performed in the sagittal view, and the maximum length of each kidney was measured. Measurem...

Jeffrey Traubici - One of the best experts on this subject based on the ideXlab platform.

  • Renal Pyramid echogenicity in ureteropelvic junction obstruction: correlation between altered echogenicity and differential renal function.
    Pediatric Radiology, 2008
    Co-Authors: Govind B. Chavhan, Alan Daneman, Rahim Moineddin, Valerie Langlois, Jeffrey Traubici
    Abstract:

    Background Improvement in resolution and use of high-frequency transducers in US has enabled visualization of previously unreported changes in Medullary Pyramid echogenicity in children with obstructive hydronephrosis.

  • Renal Pyramid echogenicity in ureteropelvic junction obstruction: correlation between altered echogenicity and differential renal function
    Pediatric Radiology, 2008
    Co-Authors: Govind B. Chavhan, Alan Daneman, Rahim Moineddin, Valerie Langlois, Jeffrey Traubici
    Abstract:

    Background Improvement in resolution and use of high-frequency transducers in US has enabled visualization of previously unreported changes in Medullary Pyramid echogenicity in children with obstructive hydronephrosis. Objective To determine whether these unreported changes in echogenicity and morphology of the renal Pyramids in ureteropelvic junction (UPJ) obstruction correlate with differential renal function (DRF) of the kidney as determined by technetium-99m mercaptoacetyltriglycine (^99mTc-MAG3) scan. Materials and methods Renal sonograms in 60 children with UPJ obstruction were retrospectively reviewed. Children were divided into three groups based on the echogenicity of the Pyramids: (1) normal echogenicity of the Pyramids, (2) increased echogenicity of the Pyramids with maintained corticoMedullary differentiation (CMD), and (3) loss of CMD. DRF, as determined by ^99mTc-MAG3 scan, of the obstructed kidney of ≥45% was considered normal and of ≤44% was considered abnormal based on a published study correlating histological changes with DRF. Fisher′s exact test was performed for assessing the association between DRF and altered echogenicity of the Pyramids. Results In group 1, which consisted of 13 patients with normal Pyramids on US, DRF was normal in 11 and abnormal in two. In group 2, which consisted of 33 patients with echogenic Pyramids and preserved CMD, DRF was normal in 15 and abnormal in 18. In group 3, which consisted of 14 patients with complete loss of CMD, DRF was normal in 2 and abnormal in 12. There was a strong correlation between abnormal Pyramids and DRF ( P =0.0009). The risk ratio (RR) of DRF becoming abnormal for those kidneys with abnormal echogenicity of the Pyramids with preserved CMD (group 2) compared to normal Pyramid echogenicity (group 1) was 1.56 (95% CI 1.088–2.236). The RR of DRF becoming abnormal for those kidneys with loss of CMD (group 3) compared to normal Pyramid echogenicity (group 1) was 5.571 (95% CI 1.530–20.294). Conclusion We observed that in obstructed kidneys the echogenicity of the Pyramids may be abnormal. Increased echogenicity of the Pyramids correlated weakly with abnormal DRF and does not necessarily indicate poor renal function. However, loss of CMD strongly correlated with poor renal function.

John J Cronan - One of the best experts on this subject based on the ideXlab platform.

  • renal cortical thickness measured at ultrasound is it better than renal length as an indicator of renal function in chronic kidney disease
    American Journal of Roentgenology, 2010
    Co-Authors: Michael D Beland, Nicholas L Walle, Jason T Machan, John J Cronan
    Abstract:

    OBJECTIVE. The purpose of our study was to determine whether there is a relationship between renal cortical thickness or length measured on ultrasound and the degree of renal impairment in chronic kidney disease (CKD).MATERIALS AND METHODS. From October to December 2007, 25 patients (13 men and 12 women, mean age 73 years) were identified who had CKD but were not on dialysis. The patients were from a single institution and had undergone renal ultrasound and at least three serum creatinines within 90 days. The lowest creatinine was used for estimated glomerular filtration rate (eGFR) calculation using both the Cockcroft-Gault (CG) and the Modification of Diet in Renal Disease Study (MDRD) equations. Ultrasounds were consensus reviewed by three radiologists (2 attendings and a resident) blinded to specific renal function. Cortical thickness was measured in the sagittal plane over a Medullary Pyramid, perpendicular to the capsule. Length was measured pole-to-pole. Linear regression was used for statistical a...

Oswald Steward - One of the best experts on this subject based on the ideXlab platform.

  • a re assessment of the effects of intracortical delivery of inosine on transmidline growth of corticospinal tract axons after unilateral lesions of the Medullary Pyramid
    Experimental Neurology, 2012
    Co-Authors: Oswald Steward, Kelli Sharp
    Abstract:

    This study was undertaken as part of the NIH “Facilities of Research Excellence-Spinal Cord Injury”, which supports independent replication of published studies. Here, we repeat an experiment reporting that intracortical delivery of inosine promoted trans-midline growth of corticospinal tract (CST) axons in the spinal cord after unilateral injury to the Medullary Pyramid. Rats received unilateral transections of the Medullary Pyramid and 1 day later, a cannula assembly was implanted into the sensorimotor cortex contralateral to the Pyramidotomy to deliver either inosine or vehicle. The cannula assembly was attached to an osmotic minipump that was implanted sub-cutaneously. Seventeen or 18 days post-injury, the CST was traced by making multiple injections of miniruby-BDA into the sensorimotor cortex. Rats were killed for tract tracing 14 days after the BDA injections. Sections through the cervical spinal cord were stained for BDA and immunostained for GAP43 and GFAP. Our results revealed no evidence for enhanced growth of CST axons across the midline of the dorsal column in rats that received intracortical infusion of inosine. Possible reasons for the failure to replicate are discussed.

  • Unexpected survival of neurons of origin of the Pyramidal tract after spinal cord injury.
    The Journal of Neuroscience, 2010
    Co-Authors: Jessica L. Nielson, Ilse Sears-kraxberger, Melissa K. Strong, Jamie K. Wong, Rafer Willenberg, Oswald Steward
    Abstract:

    There is continuing controversy about whether the cells of origin of the corticospinal tract (CST) undergo retrograde cell death after spinal cord injury (SCI). All previous attempts to assess this have used imaging and/or histological techniques to assess upper motoneurons in the cerebral cortex. Here, we address the question in a novel way by assessing Wallerian degeneration and axon numbers in the Medullary Pyramid of Sprague Dawley rats after both acute SCI, either at cervical level 5 (C5) or thoracic level 9 (T9), and chronic SCI at T9. Our findings demonstrate that only a fraction of a percentage of the total axons in the Medullary Pyramid exhibit any sign of degeneration at any time after SCI—no more so than in uninjured control rats. Moreover, design-based counts of myelinated axons revealed no decrease in axon number in the Medullary Pyramid after SCI, regardless of injury level, severity, or time after injury. Spinal cord-injured rats had fewer myelinated axons in the Medullary Pyramid at 1 year after injury than aged matched controls, suggesting that injury may affect ongoing myelination of axons during aging. We conclude that SCI does not cause death of the CST cell bodies in the cortex; therefore, therapeutic strategies aimed at promoting axon regeneration of the CST in the spinal cord do not require a separate intervention to prevent retrograde degeneration of upper motoneurons in the cortex.

Harald Hefter - One of the best experts on this subject based on the ideXlab platform.

  • bilateral Medullary Pyramid infarction
    Neurology, 2005
    Co-Authors: Philipp Zickler, Rudiger J Seitz, Hanspeter Hartung, Harald Hefter
    Abstract:

    Medial Medullary infarcts account for fewer than 1% of vertebrobasilar strokes and rarely occur bilaterally.1,2 Typical findings include hemiparesis sparing the face, dysarthria, and hypoglossal nerve palsy. In our patient, tetraparesis progressed within 3 days to severe tetraspasticity with tetanic startle reactions and autonomic dysregulation. Brain MRI showed an old …