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Plasma homocysteine levels and cardiovascular mortality in patients with end-stage renal disease
Hyperhomocysteinemia is considered an independent risk factor for atherosclerosis in patients with normal renal function. Plasma homocysteine (Hcy) is increased in patients with chronic renal failure (CRF) and could be linked to their high cardiovascular (CV) morbidity and mortality. We prospectively studied 77 patients (47 males and 30 females aged 62.85 ± 1.53 yrs) who had been on maintenance hemodialysis (HD) (4 hr/×3/week) for 65.5 ± 7.23 months. Patients were followed-up for 44 months. At baseline, blood samples were taken for hemoglobin (Hb), total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, serum calcium, serum phosphates, parathyroid hormone (PTH), Hcy, vitamin B12, serum and erythrocyte folate and methylentetrahydrofolate-reductase (t-MTH-FR) genotype determination. Plasma Hcy levels of patients were divided into four quartiles. The univariate analysis demonstrated a significant relationship between Hcy and diastolic blood pressure (BP) (r=0.45; p=0.003), and both plasma (r=-0.30; p=0.03) and erythrocyte (r=-0.48; p=0.01) folate levels and CV score (r=0.39; p=0.007). Kaplan-Meier analysis showed that the mortality rate due to CV events was statistically significantly higher in the 4th Hcy quartile (68%; 12 patients) vs. the 3rd quartile (12%; two patients), the 2nd quartile (28%; four patients) and the 1st quartile (14%; two patients) (log-rank test p=0.02). Cox's regression analysis for CV survival showed that Hcy was a positive CV mortality predictor (β=0.02; hazard ratio=1.031; 95% confidence interval (95% CI): 1.013-1.050; p=0.001), while LDL cholesterol and albumin related negatively to CV mortality (LDL cholesterol: β=-0.02; hazard ratio=0.095; 95% CI: 0.0957-0.0997; p=0.035; albumin: P=-2.35; hazard ratio=0.097; 95% CI: 0.011-0.847; p=0.026). Our results show that Hcy is a strong independent mortality predictor in HD patients with a 3% increase in mortality for each 1 μmol/L increase in plasma Hcy concentration. This agrees with previous findings confirming the role of Hcy in predicting CV risk factors in uremic patients
Behaviour of regional adrenergic outflow in mild-to-moderate renal failure
OBJECTIVES: Chronic renal failure is characterized by a marked sympathetic activation. No information exists, however, as to whether the adrenergic overdrive is confined to selected vascular districts or is rather generalized to the whole cardiovascular system. METHODS: In 15 patients aged 60.5 ± 2.0 years (mean ± SEM) with stable chronic renal failure belonging to stage 2-3 of the Kidney Foundation classification and in 12 age-matched healthy controls, we measured arterial blood pressure (Finapres), heart rate (ECG), venous plasma norepinephrine (high-performance liquid chromatography) and postganglionic sympathetic nerve traffic in skeletal muscle and skin areas (microneurography). Muscle and skin nerve traffic measurements were made in a randomized sequence over two periods of 30 min each, spaced by a 20-30-min interval. Measurements also included evaluation of skin sympathetic responses to emotional stimuli. RESULTS: Muscle sympathetic nerve traffic was markedly and significantly greater in renal failure patients compared with controls (58.2 ± 3.6 vs. 36.8 ± 5.7 bursts/100 heart beats, P < 0.01), with this also being the case for plasma norepinephrine (380.6 ± 63 vs. 210.8 ± 29 pg/ml, P < 0.05). By contrast, skin sympathetic nerve traffic was superimposable in the two groups (11.5 ± 0.8 vs. 12.7 ± 1.7 bursts/minute, P = not significant), this being the case also for the responses to emotional arousal. CONCLUSION: These data provide the first evidence that the sympathetic activation characterizing renal failure is not generalized to the entire cardiovascular system. This may depend on the fact that the two sympathetic districts are governed by mechanisms that are differently affected by the chronic uraemic state
Influenza dell’Acetate Free Biofiltration (AFB) sui livelli ematici di omocisteina in pazienti uremici
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Variations on the Author
“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
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