AMFORM, a new mass-based model for the calculation of the unit formula of amphiboles from electron microprobe analyses

In this work, we have studied the relationships between mass concentration and unit formula of amphibole using 114 carefully selected high-quality experimental data, obtained by electron microprobe (EMP) + single-crystal X‑ray structure refinement (SREF) ± secondary-ion mass spectrometry (SIMS) analyses, of natural and synthetic Li-free monoclinic species belonging to the Ca and Na-Ca subgroups, and 75 Li-free and Mn-free C2/m end-members including oxo analogs of Ca amphiboles. Theoretical considerations and crystal-chemical driven regression analysis allowed us to obtain several equations that can be used to: (1) calculate from EMP analyses amphibole unit-formulas consistent with SREF±SIMS data, (2) discard unreliable EMP analyses, and (3) estimate WO2– and Fe3+ contents in Li-free C2/m amphiboles with relatively low Cl contents (≤1 wt%). The AMFORM approach mostly relies on the fact that while the cation mass in Cl-poor amphiboles increases with the content of heavy elements, its anion mass maintains a nearly constant value, i.e., 22O + 2(OH,F,O), resulting in a very well-defined polynomial correlation between the molecular mass and the cation mass per gram (R2 = 0.998). The precision of estimating the amphibole formula [e.g., TSi ± 0.02, CAl ± 0.02, A(Ca+Na+K) ± 0.04 apfu] is 2–4 times higher than when using methods published following the last IMA recommended scheme (2012). It is worth noting that most methods using IMA1997 recommendations (e.g., PROBE-AMPH) give errors that are about twice those of IMA2012-based methods. A linear relation between WO2– and the sum of C(Ti, Fe3+) and A(Na+K) contents, useful to estimate the iron oxidation state of highly oxidized amphiboles typical of post-magmatic processes, is also proposed. A step by step procedure (Appendix1 1) and a user-friendly spreadsheet (AMFORM.xlsx, provided as supplementary material1) allowing one to calculate amphibole unit-formulas from EMP analyses are presented. This work opens new perspectives on the unit-formula calculation of other minerals containing OH and structural vacancies (e.g., micas)

Direct-acting antivirals and hepatocellular carcinoma in chronic hepatitis C: A few lights and many shadows

With the introduction of direct-acting antiviral agents (DAA), the rate of sustained virological response (SVR) in the treatment of hepatitis C virus (HCV) has radically improved to over 95%. Robust scientific evidence supports a beneficial role of SVR after interferon therapy in the progression of cirrhosis, resulting in a decreased incidence of hepatocellular carcinoma (HCC). However, a debate on the impact of DAAs on the development of HCC is ongoing. This review aimed to analyse the scientific literature regarding the risk of HCC in terms of its recurrence and occurrence after the use of DAAs to eradicate HCV infection. Among 11 studies examining HCC occurrence, the de novo incidence rate ranged from 0 to 7.4% (maximum follow-up: 18 mo). Among 18 studies regarding HCC recurrence, the rate ranged from 0 to 54.4% (maximum "not well-defined" followup: 32 mo). This review highlights the major difficulties in interpreting data and reconciling the results of the included studies. These difficulties include heterogeneous cohorts, potential misclassifications of HCC prior to DAA therapy, the absence of an adequate control group, short follow-up times and different kinds of follow-up. Moreover, no clinical feature-based scoring system accounts for the molecular characteristics and pathobiology of the tumours. Nonetheless, this review does not suggest that there is a higher rate of de novo HCC occurrence or recurrence after DAA therapy in patients with previous HCV infection. \ua9 2018 The Author(s). Published by Baishideng Publishing Group Inc. All rights reserved

Corso teorico/ pratico di Nefro-Cardiologia

Il presente corso teorico/pratico è finalizzato alla gestione del paziente iperteso ovvero un soggetto affetto di ipertensione arteriosa probabilmente portatore oltre che di disfunzione renale, di patologia cardiovascolare. Lo scopo del corso è quello di ottimizzare, attraverso la corretta interpretazione del dato laboratoristico e strumentali, la gestione del danno d’organo renale e vascolare e cardiologico indotto dall’ipertensione arteriosa. Inoltre suggerire anche le indagini diagnostiche più appropriate per approfondire tale patologia, anche alla luce della recente pubblicazione delle linee guida ESH/ESC 2007 alla luce dei più recenti trial; andrà presa in esame la personalizzazione della terapia con particolare riferimento al dosaggio delle diverse terapie, considerata la gravità dello stato ipertensivo di base. Si intende realizzare un progetto ECM sul danno cardiovascolare e renale indotta dall’ ipertensione con l’obiettivo di verificarne l’incidenza, fornendo ai partecipanti(30 medici di medicina generale delle ASL RMA e B) elementi utili a facilitarne l’individuazione precoce ed a migliorarne sia l’approccio sia clinico che terapeutico alla luce delle nuove linee guida ESH/ESC 2007 alla luce dei più recenti trial. Ciò sarà dissertato soprattutto attraverso l’analisi e la discussione pratica in aula ed in ambulatorio di casi clinici

Ischemic nephropathy: proteinuria and renal resistance index could suggest if revascularization is recommended

Background: The aim of endovascular therapy in renal artery stenosis (RAS) is to preserve renal function and have a better hypertension control. The purpose of our study was to determine which biochemical and instrumental parameters could predict a better renal outcome in patients with RAS treated with percutaneous transluminal angioplasty and stenting (RPTAS). Methods: We performed an observational study based on 40 patients with RAS who met the following criteria before revascularization: urinary protein excretion of over 250 mg/24 h, normal renal function, and/or mild-moderate renal insufficiency (I, II, and III levels of classification of chronic kidney disease, K-DOQI). Results: Assessment at 12 months after RPTAS showed in 20 patients (Group A) that proteinuria serum creatinine (Scr) and creatinine clearance (CrCl) significantly worsened from the baseline; whereas in 20 patients (Group B) proteinuria remained unchanged and the renal function improved after the procedure. Conclusions: In our study, the decline of renal function after RPTAS is associated with an elevated renal resistance index (RI) in both kidneys (0.83 +/- 0.2) and preexisting proteinuria

Mitral Valve Replacement with a Third Generation Porcine Valve: an Italian Multicentered Study

Postoperative outcomes of 3rd generation porcine bioprosthesis for mitral valve replacement (MVR) have been poorly addressed. The objective of this study was to perform an independent, retrospective, multicenter study on outcomes of patients undergoing MVR with Mosaic (Medtronic Inc., Minneapolis, MN) porcine bioposthesis

Effect of direct-acting antivirals on future occurrence of hepatocellular carcinoma in compensated cirrhotic patients

Background: The achievement of high rates of sustained virological response (SVR) with direct-acting antivirals (DAAs) in hepatitis C virus (HCV) infected patients will reduce decompensating terminal events. Aims: To investigate whether hepatocellular carcinoma (HCC) occurrence could change due to the DAA-induced increase in life-expectancy. Methods: A Markov model was built on clinical data of 494 cirrhotic patients and available literature to estimate probabilities of \u201cdeath before HCC\u201d and of \u201cHCC occurrence\u201d without and with DAA. Results: In comparison to untreated patients, DAA therapy reduced the 20-year mortality before HCC by 21.9% in patients without varices and by 21.5% in those with varices, considering an SVR of 95% and no direct effect on hepatocarcinogenesis. Tumour occurrence increased by 5%\u20138.2% and the proportion of HCCs diagnosed in compensated stages increased to >98%. If we consider DAA as having \u201canti-tumoral\u201d effects, the benefit becomes greater, achieving a 20-year survival of 81.5% in patients without varices, and 52.2% in patients with varices. Instead, if we consider DAA as having a \u201cpro-tumoral\u201d effect, then, the increased incidence of HCC nullifies the survival benefits. Conclusion: DAAs drastically reduce the mortality caused by the liver function worsening, increasing the proportion of HCCs diagnosed in compensated stages. Knowledge of the DAA effect on hepatocarcinogenesis remains pivotal