1,721,157 research outputs found
Response to endothelial nitric oxide synthase polymorphism rs3918226 associated with hypertension does not affect plasma nitrite levels in healthy subjects
No full text
Genetics of human arterial hypertension
No full textAlthough everybody agrees that each individual's blood pressure variance is under substantial genetic control, its quantitative estimates vary from 35 to 70%, according to the different experimental designs. The problem is that, in spite of such substantial contribution, the discovery of the "genes that cause hypertension" has been quite discouraging. This is indeed caused by the multifactorial nature of the disease and no improvement is to be expected without dissecting hypertension in its major pathogenetic pathways. As a paradigm of such a dissection, we present the data on adducin system, that proved to be relevant for a common form of salt sensitive in humans and the genetic hypertension of MHS rats
Le alterazioni metaboliche del paziente nefropatico
No full textNei soggetti sani, i reni regolano l’omeostasidel calcio e del fosforo attraverso il meccanismo di riassorbimento e secrezione tubulare.
Nei pazienti affetti da patologia renale cronica (CKD, Chronic Kidney Disease), il mantenimento omeostatico risulta essere seriamente compromesso, causando una serie di alterazioni metaboliche importanti.
L’alterazione della funzionalità renale si ripercuote sul metabolismo osseo, quindi, si parla di osteodistrofia renale: le numerose variazioni biochimiche nei livelli di Ca, P, vitamina D, PTH (Parathyroid Hormone), fattore di crescita dei fibroblasti-23 (FGF-23,
Fibroblastic Growth Factor-23), i cambiamenti nella morfologia, nel volume, nel turnover e
nella mineralizzazione delle ossa, le calcificazioni vascolari e di altri tessuti molli vengono
inclusi sotto la definizione di “Chronic Kidney
Disease Mineral and Bone Disorders” (CKD-
MBD), disordine sistemico del metabolismo
minerale.
Nonostante le prime manifestazioni cliniche del CKD-MBD siano legate ad alterazioni di laboratorio (iperfosforemia, deficit di vitamina
D, iperparatiroidismo secondario – SHPT, Secondary Hyperparathyroidism –, ipocalcemia)e a fratture ossee, la più grave complicanza rimane l’insorgenza delle calcificazioni vascolari, che sono presenti nel 69% dei pazienti in
dialisi e che causano elevata morbidità e mortalità.
Risulta, quindi, necessario adottare strategie terapeutiche: agenti farmacologici relativamente nuovi come sevelamer, analoghi del calcitriolo e calciomimetici possono essere somministrati singolarmente o in combinazione
per cercare di minimizzare le complicanze associate ad iperfosfatemia e a SHPT
Sevelamer for hyperphosphataemia in kidney failure : controversy and perspective
No full textThe term ‘chronic kidney disease–mineral and bone disorder’ (CKD–MBD), coined in 2006, was introduced in a position statement by the Kidney Disease: Improving Global Outcomes (KDIGO) organization. According to the KDIGO guidelines, CKD–MBD is a systemic disorder and patients with vascular or valvular calcifications should be included in the group with the greatest cardiovascular risk. Therefore, the presence or absence of calcification is a key factor in strategy decisions for such patients. In particular, it is recommended that the use of calcium-based phosphate binders should be restricted in patients with hypercalcaemia, vascular calcification, low levels of parathyroid hormone (PTH) or adynamic bone disease. In this respect, it should be underscored that treatment with phosphate-binding agents can normalise the levels of phosphate and PTH, but the use of calcium carbonate can favour the progression of vascular calcifications. There is evidence of reduced progression of vascular calcification in patients treated with sevelamer compared with high doses of calcium-based binders, but there is as yet no strong evidence regarding hard outcomes, such as mortality or hospitalization, to support the use of one treatment over another. Nevertheless, a number of experimental and observational findings seem to suggest that sevelamer should be preferred over calcium-based binders, in as much as these can increase cardiovascular mortality when used in high doses. A threshold dose below which calcium-based binders can be used safely in CKD patients with hyperphosphatemia has yet to be established
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
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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