1,721,002 research outputs found
Think of Oxalate when Using Ascorbate Supplementation to Optimize Iron therapy in Dialysis Patients ( Letter)
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Calcimimetics, phosphate binders, vitamin D and its analogues for treating secondary hyperparathyroidism in chronic kidney disease: guideline from the Italian Society of Nephrology.
No full textImpact of food quantity and quality on the biochemical risk of renal stone formation
No full textObjective: This study evaluated the role of body mass index (BMI) and dietary potential renal acid load (PRAL) with urinary saturation for calcium oxalate (US-CaOx), calcium phosphate (US-CaP) and uric acid (US-UA) in renal stone formers.Materials and methods: A retrospective analysis was conducted of laboratory data collected on 442 renal stone-forming patients. Demographic information, BMI and 24 h urinary samples were collected from patients on their regular diets. PRAL was calculated as the Load of Acid to Kidney Evaluation (LAKE) score through a short questionnaire.Results: Urinary risk factors, but also inhibitors of calcium stone formation such as magnesium, tended to increase in relation to BMI (p=.000). Urinary pH (p=.002) and ammonium/sulfate ratio (p=.000) were negatively related to BMI. This resulted in a positive correlation between BMI and US-UA (p = .000), whereas US-CaOx and US-CaP were not influenced by BMI. LAKE score was positively correlated with US-CaOx (p = .022) and US-CaP (p = .000) as a consequence of the inverse relationship between LAKE score and citrate (p = .000). Multiple linear regression analysis identified BMI (p=.009) and male gender (p = .002) as independent predictors of US-UA, and LAKE score (p = .004) and age (p = .001) as independent predictors of US-CaP.Conclusions: BMI, which depends on excessive intake of energy from food, is not related to an increased biochemical risk of calcium stone formation, which is more dependent on the renal acid load of the diet. In contrast, obesity is associated with an increased risk of uric acid stone formation due to insulin resistance, impaired ammoniagenesis and low urinary pH
A multiregional Italian cohort of 24-hour urine metabolic evaluation in renal stone formers
No full textBACKGROUND. Nephrolithiasis is a common condition with several studies documenting an increased prevalence over the past four decades. EAU and AUA guidelines recommend 24-hour urine metabolic evaluation in high-risk stone formers. Aim of this study is to retrospectively evaluate the first three years of experience with LithoTest (R) (Biohealth Italia Srl, Turin, Italy) through the analysis of demographic, clinical and biochemical data collected from a large cohort of patients with kidney stones.METHODS. We retrospectively analyzed data from the LithoCenter database, including data from outpatient consultations, between January 2007 and December 2009 from all over Italy. LithoTest (R) was performed through a 24-hour urine collection and included measurements of urine volume and pH, 24-hour excretion of creatinine as well as main cations and anions, including calcium, magnesium sodium potassium, ammonium, uric acid, oxalate, citrate, phosphate, inorganic sulphate and chloride. Urine state of saturation for calcium oxalate (beta CaOx), calcium hydrogen phosphate or brushite (beta bsh) and uric acid (beta UA) were also calculated by means of the computer program LithoRisk. Brand's test for cystinuria was also carried out. Statistical analysis was performed using the S-PSS software v. 22.0.RESULTS. The number of patients with data available for analysis was 435, of whom 236 were male (54%) and 199 female (46%). Complete 24-hour urine measurements were available for all 435 patients. Compared to men, women had significantly lower values for creatinine, urate, oxalate, phosphate, sodium, potassium, magnesium and chloride excretion, whereas 24-hour pH and citrate excretion were higher. No significant differences were found for the other examined variables. beta CaOx and beta UA were significantly higher in men than women, whereas no significant difference was found for beta bsh. There was a direct relationship between calcium and sodium urine excretion. Excessive sodium excretion was recorded in 191 patients (44%) and low urine volumes in 201 (46.2%). Hyperoxaluria was observed in 118 patients (27.3%), hypercalciuria in 115 (26.6%), hyperuricosuria in 153 (35.4%), hypomagnesuria in 96 (22.2%), and hypocitraturia in 134 patients (31%). Hyperexcretion of sodium, hypocitraturia and hyperoxaluria were most frequent in males. beta CaOx was significantly higher in the setting of hypercalciuria, hypocitraturia, hyperoxaluria and urine pH below 5.5.CONCLUSIONS. Our findings in a large cohort of high-risk stone-forming patients show significant differences in urinary metabolic profiles between men and women. Carrying on the collection and analysis of data by LithoTest (R) from 2009 to 2015 and matching urinary and dietary data could eventually improve our understanding on the metabolic profile of stone-formers in Italy
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Letter to the Editor: protective effect of vitamin C supplementation in dialysis patients: not all that glitters...
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Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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