Purpose: To compare two methods for assessing the single kidney glomerular filtration rate (SK-GFR) in humans using dynamic contrast-enhanced (DCE)-MRI. Materials and Methods: Images were acquired from 39 separate MR studies of patients with atherosclerotic renovascular disease (ARVD). Data from the kidneys and descending aorta were analyzed using both a Rutland-Patlak plot and a compartmental model. MR estimates of the SK-GFR were compared with standard radioisotope measures in a total of 75 kidneys. Results: Estimates of renal function using both techniques correlated well with radioisotope-assessed SK-GFR (Spearman's ϭ 0.81, Rutland-Patlak; ϭ 0.71, compartmental model). The Rutland-Patlak approach provided a near one-toone correspondence, while the compartmental method tended to overestimate SK-GFR. However, the compartmental model fits to the experimental data were significantly better than those obtained using the Rutland-Patlak approach. Conclusion: DCE-MRI of the kidneys provides data that correlate well with reference measures of SK-GFR. However, further work, including image registration, is needed to isolate measurement of glomerular filtration to the level of the renal cortex.

Objective. We analyzed misinformation about Ebola circulating on Twitter and Sina Weibo, the leading Chinese microblog platform, at the outset of the global response to the 2014-2015 Ebola epidemic to help public health agencies develop their social media communication strategies. We obtained and analyzed a 1% random sample of tweets containing the keyword Ebola. We retrieved all Sina Weibo posts with Chinese keywords for Ebola for analysis. We analyzed changes in frequencies of keywords, hashtags, and Web links using relative risk (RR) and c 2 feature selection algorithm. We identified misinformation by manual coding and categorizing randomly selected sub-datasets.Results. We identified two speculative treatments (i.e., bathing in or drinking saltwater and ingestion of Nano Silver, an experimental drug) in our analysis of changes in frequencies of keywords and hashtags. Saltwater was speculated to be protective against Ebola in Batch 1 tweets but their mentions decreased in Batch 2 (RR50.11 for "salt" and RR50.14 for "water"). Nano Silver mentions were higher in Batch 2 than in Batch 1 (RR510.5). In our manually coded samples, Ebola-related misinformation constituted about 2% of Twitter and Sina Weibo content. A range of 36%-58% of the posts were news about the Ebola outbreak and 19%-24% of the posts were health information and responses to misinformation in both batches. In Batch 2, 43% of Chinese microblogs focused on the Chinese government sending medical assistance to Guinea.Conclusion. Misinformation about Ebola was circulated at a very low level globally in social media in either batch. Qualitative and quantitative analyses of social media posts can provide relevant information to public health agencies during emergency responses.

Undiagnosed CKD is common in diabetes. Current screening strategies, based on creatinine or albuminuria, fail to identify a considerable number of subjects with CKD. Incorporating eGFR into screening for CKD would identify individuals earlier in the natural history of the disease and enable early effective treatment to delay progression of CKD.

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RAB is well tolerated even in patients with bilateral severe RAS and reduced mortality in a large group of ARVD patients. We recommend all ARVD patients be considered for RAB therapy unless an absolute contra-indication exists. Intolerance of these agents due to renal dysfunction should be considered an emerging indication for renal revascularization to facilitate their re-introduction.

We report the results of a preregistered, cluster randomized controlled trial of a mathematics learning intervention known as interleaved practice. Whereas most mathematics assignments consist of a block of problems devoted to the same skill or concept, an interleaved assignment is arranged so that no 2 consecutive problems require the same strategy. Previous small-scale studies found that practice assignments with a greater proportion of interleaved practice produced higher test scores. In the present study, we assessed the efficacy and feasibility of interleaved practice in a naturalistic setting with a large, diverse sample. Each of 54 7th-grade mathematics classes periodically completed interleaved or blocked assignments over a period of 4 months, and then both groups completed an interleaved review assignment. One month later, students took an unannounced test, and the interleaved group outscored the blocked group, 61% versus 38%, d ϭ 0.83. Teachers were able to implement the intervention without training, and they later expressed support for interleaved practice in an anonymous survey they completed before they knew the results of the study. Although important caveats remain, the results suggest that interleaved mathematics practice is effective and feasible. Educational Impact and Implications StatementEvery school day, many millions of mathematics students complete a set of practice problems that can be solved with the same strategy, such as adding fractions by finding a common denominator. In an alternative approach known as interleaved practice, practice problems are arranged so that no two consecutive problems can be solved by the same strategy, and this approach forces students to choose an appropriate strategy for each problem on the basis of the problem itself. We conducted a large randomized classroom study and found that a greater emphasis on interleaved practice dramatically improved test scores.

Numerous anatomical and functional changes occurring in the aging kidney lead to reduced glomerular filtration rate, lower renal blood flow and impaired renal autoregulation. The elderly are especially vulnerable to the development of renal dysfunction and in this population acute renal failure (ARF) is a common problem. ARF is often iatrogenic and multifactorial; common iatrogenic combinations include pre-existing renal dysfunction and exposure to nephrotoxins such as radiocontrast agents or aminoglycosides, use of NSAIDs in patients with congestive cardiac failure and use of ACE inhibitors and diuretics in patients with underlying atherosclerotic renal artery stenosis. The aetiology of ARF is classically grouped into three categories: prerenal, intrinsic and postrenal. Prerenal ARF is the second most common cause of ARF in the elderly, accounting for nearly one-third of all hospitalized cases. Common causes can be grouped into true volume depletion (e.g. decreased fluid intake), decreased effective blood volume (e.g. systemic vasodilation) and haemodynamic (e.g. renal artery stenosis, NSAID use). Acute tubular necrosis (ATN) is the most common cause of intrinsic ARF and is responsible for over 50% of ARF in hospitalized patients, and up to 76% of cases in patients in intensive care units. ATN usually occurs after an acute ischaemic or toxic event. The pathogenesis of ATN involves an interplay of processes that include endothelial injury, microvascular flow disruption, tubular hypoxia, dysfunction and apoptosis, tubular obstruction and trans-tubular back-leak. Vasculitis causing ARF should not be missed as this condition is potentially life threatening. The likelihood of a postrenal cause for ARF increases with age. Benign prostatic hypertrophy, prostatic carcinoma and pelvic malignancies are all important causes. Early identification of ARF secondary to obstruction with renal imaging is essential, and complete or partial renal recovery usually ensues following relief of the obstruction.A comprehensive medical and drug history and physical examination are all invaluable. Particular attention should be paid to the fluid status of the patient (skin turgor, jugular venous pressure, lying and standing blood pressure, urine output). Urinalysis should be performed to detect evidence of proteinuria and haematuria, which will aid diagnosis. Fractional excretion of sodium and urine osmolality may be measured but the widespread use of diuretics in the elderly gives rise to unreliable results. Renal imaging, usually ultrasound scanning, is routinely performed for assessment of renal size and to exclude urinary obstruction. In some cases, renal biopsy is necessary to provide specific diagnostic information. The general principles of managing ARF include treatment of life-threatening features such as shock, respiratory failure, hyperkalaemia, pulmonary oedema, metabolic acidosis and sepsis; stopping and avoiding administration of nephrotoxins; optimization of haemodynamic and fluid status; adjustment of drug dosage appropria...