Atrial fibrillation: Epigenetic aspects and role of sodium-glucose cotransporter 2 inhibitors.

Atrial fibrillation (AF) is the most frequent arrhythmia and is associated with substantial morbidity and mortality. Pathophysiological aspects consist in the activation of pro-fibrotic signaling and Ca2+ handling abnormalities at atrial level. Structural and electrical remodeling creates a substrate for AF by triggering conduction abnormalities and cardiac arrhythmias. The care of AF patients focuses predominantly on anticoagulation, symptoms control and the management of risk factors and comorbidities. The goal of AF therapy points to restore sinus rhythm, re-establish atrioventricular synchrony and improve atrial contribution to the stroke volume. New layer of information to better comprehend AF pathophysiology, and identify targets for novel pharmacological interventions consists of the epigenetic phenomena including, among others, DNA methylation, histone modifications and noncoding RNAs. Moreover, the benefits of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in diabetic and non-diabetic patients at cardiovascular risk as well as emerging evidence on the ability of SGLT2i to modify epigenetic signature in cardiovascular diseases provide a solid background to investigate a possible role of this drug class in the onset and progression of AF. In this review, following a summary of pathophysiology and management, epigenetic mechanisms in AF and the potential of sodium-glucose SGLT2i in AF patients are discussed.

Common carp exposed to binary mixtures of Cd(II) and Zn(II): A study on metal bioaccumulation and ion-homeostasis.

The aquatic environment receives a wide variety of contaminants that interact with each other, influencing their mutual toxicity. Therefore, studies of mixtures are needed to fully understand their deleterious effects on aquatic organisms. In the present experiment, we aimed to assess the effects of Cd and Zn mixtures in common carp during a one-week exposure. The used nominal waterborne metal levels were 0.02, 0.05 and 0.10 µM for Cd and 3, 7.5 and 15 µM for Zn. Our results showed on the one hand a fast Cd increase and on the other hand a delayed Zn accumulation. In the mixture scenario an inhibition of Cd accumulation due to Zn was marked in the liver but temporary in the gills. For Zn, the delayed accumulation gives an indication of the efficient homeostasis of this essential metal. Between the different mixtures, a stimulation of Zn accumulation by Cd rather than an inhibition was seen in the highest metal mixtures. However, when compared to an earlier single Zn exposure, a reduced Zn accumulation was observed. Metallothionein gene expression was quickly activated in the analysed tissues suggesting that the organism promptly responded to the stressful situation. Finally, the metal mixture did not alter tissue electrolyte levels.

Physiological performance of common carp (Cyprinus carpio, L., 1758) exposed to a sublethal copper/zinc/cadmium mixture.

In a natural ecosystem, fish are subjected to a multitude of variable environmental factors. It is important to analyze the impact of combined factors to obtain a realistic understanding of the mixed stress occurring in nature. In this study, the physiological performance of juvenile common carp (Cyprinus carpio) exposed for one week to an environmentally relevant metal mixture (4.8 µg/L of copper; 2.9 µg/L of cadmium and 206.8 µg/L of zinc) and to two temperatures (10 °C and 20 °C), were evaluated. After 1, 3 and 7 days, standard (SMR) and maximum metabolic rate (MMR) were measured and aerobic scope (AS) was calculated. In addition, hematocrit, muscle lactate, histology of the gills and metal accumulation in gills were measured. While SMR, MMR and AS were elevated at the higher temperature, the metal mixture did not have a strong effect on these parameters. At 20 °C, SMR transiently increased, but no significant changes were observed for MMR and AS. During metal exposure, hematocrit levels were elevated in the 20 °C group. The bioaccumulation of Cd in the gills reflected the increased metabolic rate at the higher temperature, with more accumulation at 20 °C than at 10 °C. Anaerobic metabolism was not increased, which corresponds with the lack of significant histopathological damage in the gill tissue. These results show that common carp handled these metal exposures well, although increased temperature led to higher Cd accumulation and necessitated increased hematocrit levels to maintain aerobic performance.

Antagonistic bioaccumulation of waterborne Cu(II) and Cd(II) in common carp (Cyprinus carpio) and effects on ion-homeostasis and defensive mechanisms.

In the aquatic environment, metals are present as mixtures, therefore studies on mixture toxicity are crucial to thoroughly understand their toxic effects on aquatic organisms. Common carp (Cyprinus carpio) were used to assess the effects of short-term Cu(II) and Cd(II) mixtures, using a fixed concentration of one of the metals, representing 25 % of its individual 96h-LC50 (concentration lethal for 50 % of the population) combined with a variable concentration of the other metal corresponding to 10, 25 or 50 % of its 96h-LC50, and vice versa. Our results showed a fast Cu and Cd bioaccumulation, with the percentage of increase in the order gill > liver > carcass. An inhibitory effect of Cu on Cd uptake was observed; higher Cu concentrations at fixed Cd levels resulted in a decreased accumulation of Cd. The presence of the two metal ions resulted in losses of total Na, K and Ca. Fish tried to compensate for the Na loss through the induction of the genes coding for Na+/K+-ATPase and H+-ATPase. Additionally, a counterintuitive induction of the gene encoding the high affinity copper transporter (CTR1) occurred, while a downregulation was expected to prevent further metal ion uptake. An induction of defensive mechanisms, both metal ion binding protein and anti-oxidant defences, was observed. Despite the metal accumulation and electrolyte loss, the low mortality suggest that common carp is able to cope with these metal levels, at least during a one-week exposure.

Investigating the effects of a sub-lethal metal mixture of Cu, Zn and Cd on bioaccumulation and ionoregulation in common carp, Cyprinus carpio.

The aquatic environment is continuously under threat because it is the final receptor and sink of waste streams. The development of industry, mining activities and agriculture gave rise to an increase in metal pollution in the aquatic system. Thus a wide occurrence of metal mixtures exists in the aquatic environment. The assessment of mixture stress remains a challenge considering that we can not predict the toxicity of a mixture on the basis of single compounds. Therefore the analysis of the effects of environmentally relevant waterborne mixtures is needed to improve our understanding of the impact of metal pollution in aquatic ecosystems. Our aim was to assess whether 10 % of the concentration of the 96 h LC50 (the concentration that is lethal to 50 % of the population in 96 h) of individual metal exposures can be considered as a "safe" concentration when applied in a trinomial mixture. Therefore, common carp were exposed to a sublethal mixture of Cu 0.07 ±â€¯0.001 µM (4.3 ±â€¯0.6 µg/L), Zn 2.71 ±â€¯0.81 µM (176.9 ±â€¯52.8 µg/L) and Cd 0.03 ±â€¯0.0004 µM (3.0 ±â€¯0.4 µg/L) at 20 °C for a period of one week. Parameters assessed included survival rate, bioaccumulation and physiological biomarkers related to ionoregulation and defensive mechanisms such as MT induction. Our results showed a sharp increase in Cu and Cd concentration in gills within the first day of exposure while Zn levels remained stable. The accumulation of these metals led to a Na drop in gills, liver and muscle as well as a decreased K content in the liver. Biomarkers related to Na uptake were also affected: on the first day gene expression for H+-ATPase was transiently increased while a concomitant decreased gene expression of the Na+/H+ exchanger occurred. A fivefold induction of metallothionein gene expression was reported during the entire duration of the experiment. Despite the adverse effects on ionoregulation all fish survived, indicating that common carp are able to cope with these low metal concentrations, at least during a one week exposure.

Limited oxidative stress in common carp (Cyprinus carpio, L., 1758) exposed to a sublethal tertiary (Cu, Cd and Zn) metal mixture.

Analyzing effects of metal mixtures is important to obtain a realistic understanding of the impact of mixed stress in natural ecosystems. The impact of a one-week exposure to a sublethal metal mixture containing copper (4.8 µg/L), cadmium (2.9 µg/L) and zinc (206.8 µg/L) was evaluated in the common carp (Cyprinus carpio). To explore whether this exposure induced oxidative stress or whether defense mechanisms were sufficiently fitting to prevent oxidative stress, indicators of apoptosis (expression of caspase 9 [CASP] gene) and of oxidative stress (malondialdehyde [MDA] level and xanthine oxidase [XO] activity) were measured in liver and gills, as well as activities and gene expression of enzymes involved in antioxidant defense (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx], glutathione reductase [GR] and glutathione-S-transferase [GST]). The total antioxidative capacity (T-AOC) was also quantified. No proof of oxidative stress was found in either tissue but there was indication of apoptosis in the liver. CAT, GPx, GR and GST total activities were reduced after 7 days, suggesting a potential decrease of glutathione levels and risk of increased free radicals if the exposure would have lasted longer. There were no major changes in the total activities of antioxidant enzymes in the gills, but the relative expression of the genes coding for CAT and GR were triggered, suggesting a response at the transcription level. These results indicate that C. carpio is well equipped to handle these levels of metal pollution, at least during short term exposure.

Density-dependent changes in neophobia and stress-coping styles in the world's oldest farmed fish.

Farmed fish are typically reared at densities much higher than those observed in the wild, but to what extent crowding results in abnormal behaviours that can impact welfare and stress coping styles is subject to debate. Neophobia (i.e. fear of the 'new') is thought to be adaptive under natural conditions by limiting risks, but it is potentially maladapted in captivity, where there are no predators or novel foods. We reared juvenile Nile tilapia (Oreochromis niloticus) for six weeks at either high (50 g l-1) or low density (14 g l-1), assessed the extent of skin and eye darkening (two proxies of chronic stress), and exposed them to a novel object in an open test arena, with and without cover, to assess the effects of density on neophobia and stress coping styles. Fish reared at high density were darker, more neophobic, less aggressive, less mobile and less likely to take risks than those reared at low density, and these effects were exacerbated when no cover was available. Thus, the reactive coping style shown by fish at high density was very different from the proactive coping style shown by fish at low density. Our findings provide novel insights into the plasticity of fish behaviour and the effects of aquaculture intensification on one of the world's oldest farmed and most invasive fish, and highlight the importance of considering context. Crowding could have a positive effect on the welfare of tilapia by reducing aggressive behaviour, but it can also make fish chronically stressed and more fearful, which could make them less invasive.

Butyrate modulating effects on pro-inflammatory pathways in human intestinal epithelial cells.

Butyrate acts as energy source for intestinal epithelial cells and as key mediator of several immune processes, modulating gene expression mainly through histone deacetylation inhibition. Thanks to these effects, butyrate has been proposed for the treatment of many intestinal diseases. Aim of this study was to investigate the effect of butyrate on the expression of a large series of target genes encoding proteins involved in pro-inflammatory pathways. We performed quantitative real-time-PCR analysis of the expression of 86 genes encoding proteins bearing to pro-inflammatory pathways, before and after butyrate exposure, in primary epithelial cells derived from human small intestine and colon. Butyrate significantly down-regulated the expression of genes involved in inflammatory response, among which nuclear factor kappa beta, interferon-gamma, Toll like 2 receptor and tumour necrosis factor-alpha. Further confirmations of these data, including studies at protein level, would support the use of butyrate as effective therapeutic strategy in intestinal inflammatory disorders.

An "ex vivo model" contributing to the diagnosis and evaluation of new drugs in cystic fibrosis.

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) gene. About 2000 mutations have been described so far. We setup an ex vivo model of human nasal epithelial cells (HNECs) to study CF patients testing the effect of novel mutations and molecular therapies. We performed sampling (by brushing), followed by culture and analysis of HNECs using a series of molecular techniques. We performed 50 brushings from CF patients and controls. Using cultured cells, we: i) demonstrated the widely heterogeneous CFTR expression in patients and in controls; ii) defined the splicing effect of a CFTR mutation; iii) assessed the CFTR gating activity in patients bearing different mutations; iv) demonstrated that butyrate significantly enhances CFTR expression. Based on our data, we can conclude: 1) HNEC brushing is performed without anaesthesia and is well tolerated in all CF patients (children and adults); 2) HNECs can be preserved for up to 48 hours before culture allowings multicentre studies; 3) HNECs culture can be considered a suitable model to study the molecular effects of new CFTR gene mutations and/or uncertain meaning specific mutations of carriers; 4) an ex vivo model of HNECs may be used to evaluate, before human use, the effect of new drugs on patients' cells bearing specific CFTR mutations; 5) the methodology is adequate for a quantitative measurement, by fluorescence, of the CFTR gating activity of the HNECs from patients with different genotypes identifying: a) CF patients bearing two severe mutations with an activity < 10% (compared to controls - 100%); b) CF patients bearing at least a mild mutation with an activity of 10-20%; c) CF carriers (heterozygous subjects) with an activity between 40-70%.

Is it time to revise the normal range of serum uric acid levels?

The actual reference range of serum uric acid has been assessed according to its variations among healthy individuals. i.e. those without clinical evidence of gout. By this approach, serum uric acid values between 3.5 and 7.2 mg/dL in adult males and postmenopausal women and between 2.6 and 6.0 mg/dL in premenopausal women have been identified as normal in many countries. However, this definition of normal range of serum uric acid in the general population is inevitably influenced by what we consider as "normal", since the absence of gout flares does not necessarily imply the absence of uric acid-related damage. Indeed, a growing body of evidence indicates that silent deposition of monosodium urate crystals as a result of hyperuricaemia may occur and lead to early destructive skeletal changes. In addition, a growing body of evidences demonstrates that uric acid might play a pathophysiological role in many "cardio-nephro-metabolic" disorders, which seems to be independent of the deposition of monosodium urate crystals, since it is evident also for serum uric acid concentrations below the saturation point for monosodium urate. Taken together, these findings strongly suggest to carefully reconsider the concept of "asymptomaticity" for chronic hyperuricemia and to consequently revise the normal range of serum uric acid levels also considering the progressive worldwide increase of circulating levels of uric acid, which could lead to a "shift to right" (i.e. toward higher values) of normal range. In the light of the new scientific knowledge on the pathophysiological role of uric acid in human disease, a threshold value < 6.0 mg/dL (< 360 µmol/L) seems to better identify true "healthy subjects" and should reasonably be considered for all subjects.

Prediction of acute pancreatitis risk based on PIP score in children with cystic fibrosis.

BACKGROUND: Currently no tools to predict risk of acute (AP) and recurrent pancreatitis (ARP) in children with cystic fibrosis (CF) are available. We assessed the prevalence of AP/ARP and tested the potential role of Pancreatic Insufficiency Prevalence (PIP) score in a cohort of children with CF. METHODS: We identified two groups of children, on the basis of presence/absence of AP/ARP, who were compared for age at diagnosis, clinical features, genotypes and sweat chloride level. PIP score was calculated for each patient. RESULTS: 10/167 (5.9%) experienced at least one episode of AP during follow up; 10/10 were pancreatic sufficient (PS). Patients with AP/ARP showed a PIP score ≤0.25 more frequently (6/10) than patients without AP/ARP. The odds ratio (95% CI) of developing pancreatitis was 4.54 (1.22-16.92) for patients with PIP <0.25 when compared with those who have a PIP score >0.25 (p 0.0151). PIP score was correlated with sweat chloride test (p < 0.01). CONCLUSION: PIP score, PS status and normal/borderline sweat chloride levels could be applied to predict pancreatitis development in children with CF. ARP could lead to pancreatic insufficiency.

Daclatasvir: the first of a new class of drugs targeted against hepatitis C virus NS5A.

Hepatitis C virus (HCV) infection affects about 160 million people worldwide. It is treated with pegylatedinterferon (peg-IFN) and ribavirin, and in the case of patients affected by genotype 1, also with a protease inhibitor (telaprevir or boceprevir). Despite a good success rate, IFN-based combinations are contraindicated in several patients (e.g. decompensated cirrhosis, patients with psychiatric disorders, severe heart diseases or autoimmune disorders) and are associated with frequent adverse events that ultimately reduce their use. Numerous oral drugs are in an advanced phase of clinical development, and in some cases, in IFN-free combinations. This review focuses on preclinical and clinical data regarding daclatasvir (BMS-790052), which is a highly selective HCV NS5A replication complex inhibitor effective against HCV genotypes 1, 2, 3 and 4. In vitro data show that daclatasvir exerts a very potent antiviral effect against several HCV genotypes. Its pharmacokinetics is optimal and allows once-a-day oral administration. Its adverse event profile is good. Clinical data regarding its efficacy in combination with peg-IFN, ribavirin or other direct antiviral agents are impressive (rates of sustained virological response range between 60% and 100% in treatment-naïve patients). The only drawback of this drug appears to be a relatively low genetic barrier to resistance. In conclusion, daclatasvir, especially in combinations with other antiviral agents, is a very promising drug for the treatment of chronic hepatitis C.

Brand new SPINK1 and CFTR mutations in a child with acute recurrent pancreatitis: a case report.

We report a case of a 2,5 years old female, referred to our center for pancreatitis. Medical investigation revealed history of acute recurrent pancreatitis (ARP) since 1 year of age. Family history was negative for pancreatitis. Abdominal ultrasonography and magnetic resonance excluded both biliary tract stenosis and anatomic abnormalities. Calcium metabolic disorders, viral and bacterial infections were ruled out. Molecular sequencing of CFTR revealed heterozygosis for the mutation S1235R, a CFTR-related disorders associated mutation. Fecal elastase-1 (E1) was 529 µg/gr feces (normal value 200-500 µg/gr feces). No mutation of PRSS1 gene was detected but heterozygosity for p.Lys41Asn (c.123G>C), a new mutation of SPINK1 gene, was revealed. We speculate that the association of both SPINK1 and CFTR gene mutations may be responsible of ARP in our patient. Further studies need to better elucidate the role of genetic factors in ARP, as well as the influence of environmental factors.

A novel promising therapeutic option against hepatitis C virus: an oral nucleotide NS5B polymerase inhibitor sofosbuvir.

Hepatitis C virus (HCV) infection is one of the main causes of liver disease worldwide. Its treatment is currently based on the combination of peg-interferon, ribavirin, and, for patients with genotype 1, a protease inhibitor (telaprevir or boceprevir). However, interferon-based combinations are not effective in all patients. Moreover, they are contraindicated in patients who cannot receive interferon (e.g. those with decompensated cirrhosis), and are frequently associated with adverse events. Consequently, there is a need to develop new drugs to treat HCV infection. This review focuses on preclinical and clinical data regarding sofosbuvir (GS-7977), a uridine nucleotide analogue inhibitor of HCV NS5 B polymerase that is effective against HCV genotypes 1,2, 3,4 and 6. Thanks to its excellent pharmacokinetic profile, sofosbuvir can be administered in an oral single daily dose. In vitro it exerts a potent antiviral effect against HCV. Clinical data show that combined with peg-interferon and ribavirin for 12 weeks it yields SVR of about 90% in subjects with HCV genotype 1 and about 100% in patients with HCV genotype 2 or 3. Moreover, sofosbuvir and ribavirin administered for 12 weeks yield similar high SVR rate (84% for genotype 1 and 100% for genotype 2/3 patients) as well as sofosbuvir and daclatasvir (an inhibitor of NS5A) which produce SVR rate of about 100% regardless of genotype or of ribavirin employment. Safety and tolerability of sofosbuvir appear to be excellent. In conclusion, sofosbuvir especially in interferon-free combinations represents a very promising option in the treatment of chronic hepatitis C.

Treatment of horizontal canal benign paroxysmal positional vertigo: a new rehabilitation technique.

The aim of this study was to evaluate the effectiveness of a new technical variant applied to the Gufoni's manoeuvre, in the treatment of horizontal canal benign paroxysmal positional vertigo (HSC-BPPV). 87 patients with BPPV of HSC (55 women and 32 men), aged between 21 and 80 years, were randomized either to modified Gufoni's manoeuvre or to the Gufoni's manoeuvre. 93% of patients treated with modified Gufoni's manoeuvre was cured after the first treatment session, of which only 2% had a conversion into PSC-BPPV, while the Gufoni's manoeuvre led to a symptoms resolution in 88% of cases, of which 16% had a conversion into PSC-BPPV. Therefore, the modified Gufoni's manoeuvre shows the same effectiveness in the resolution of symptoms of Gufoni's manoeuvre, but it appears more effective than the latter to reduce the percentage of conversion of the HSC-BPPV into PSC-BPPV (χ(2) = 6.13, P = 0.047).

Molecular analysis and genotype-phenotype correlation in patients with antithrombin deficiency from Southern Italy.

We sequenced the SERPINC1 gene in 26 patients (11 males) with antithrombin (AT) deficiency (22 type I, 4 type II), belonging to 18 unrelated families from Southern Italy. Heterozygous mutations were identified in 15/18 (83.3%) families. Of them, eight were novel mutations, each being identified in one family. Seven clearly cause impaired protein synthesis (four frameshift, one non-stop, one splicing and one 21bp deletion). One, present in a single patient, is a missense mutation thought to be causative because: a) it is absent in 100 chromosomes from controls; b) it involves a highly conserved amino acid, whose change is predicted to impair AT activity; c) no other mutation is present in the propositus. Severe mutations (i.e. nonsense, frameshift, deletions) were invariably identified in type I patients. In type II patients, 3/4 were missense mutations; the fourth leads to a 19 nucleotides shift in the stop codon. In addition to the type of mutation, the co-existence of other predisposing factors in most patients helps explain the severity of the present type I cases (age at first event, recurrence during prophylaxis). In the five families in which there was more than one member affected, the same genotype and a concordant clinical expression of the disease were found. We conclude that the molecular bases of AT deficiency in Southern Italy are different as compared to other geographic areas, and that molecular analysis and the study of the effect of the mutation may help predict the clinical expression of the disease.

An MBL2 haplotype and ABCB4 variants modulate the risk of liver disease in cystic fibrosis patients: a multicentre study.

BACKGROUND: Cystic fibrosis is the most common lethal recessive disorder among Caucasians. Over 1500 mutations have been identified in cystic fibrosis transmembrane conductance regulator disease-gene so far. A large variability of the clinical phenotype has been observed both in cystic fibrosis patients bearing the same genotype, and in affected sibpairs. Thus, genes inherited independently from cystic fibrosis transmembrane conductance regulator could modulate the clinical expression of cystic fibrosis. METHODS: We analysed some putative modifier genes of liver cystic fibrosis phenotype (serpin 1, hemochromatosis, transferrin receptor 2, ferroportin 1, mannose binding lectin and adenosine triphospate-binding cassette subfamily B member 4) in 108 unrelated cystic fibrosis patients with and without liver involvement. RESULTS: HYPD mannose binding lectin haplotype was significantly (p<0.05) more frequent in cystic fibrosis patients with liver disease versus those without liver disease. This haplotype already related to a more severe pulmonary cystic fibrosis phenotype, is associated to a reduced MBL immunological activity. The c.834-66G>T variant of adenosine triphospate-binding cassette subfamily B member 4 gene was significantly (p<0.05) less frequent in cystic fibrosis patients with liver disease as compared to those with no liver disease. CONCLUSIONS: The HYPD mannose binding lectin haplotype may predispose a subgroup of cystic fibrosis patients to a more severe liver involvement impairing the local defence mechanisms whereas the c.834-66G>T adenosine triphospate-binding cassette subfamily B member 4 variant may enhance the activity of the protein and thus exert a protective effect toward liver disease.

Early pregnancy loss in celiac women: The role of genetic markers of thrombophilia.

BACKGROUND: Adverse pregnancy outcomes are more frequent in celiac than in non-celiac women. AIMS: To investigate a possible role of genetic prothrombotic variants in early pregnancy loss of celiac women. METHODS: Thirty-nine celiac women who had experienced early pregnancy losses (at least two losses within the first 3 months of pregnancy), and 72 celiac women with a history of one or more normal pregnancies and no pregnancy loss (controls) entered the study, at the moment of diagnosis for celiac disease. A clinical history was obtained from each woman. DNA from leukocytes was tested for: factor V Leiden (mutation G1691A), factor V R2 (H1299R), factor II (G20210A), methylenetetrahydrofolate reductase (MTHFR) (C677T and A1298C), beta-fibrinogen (-455 G>A), PAI-1 alleles 4G/5G, factor XIII (V34L), and HPA-1 (L33P). RESULTS: Age at diagnosis was significantly higher (p=0.002) in the celiac women with pregnancy losses than in controls. Of the gene variants studied, the allelic frequency of 4G variant of PAI-1, and the frequency of mutant genotypes were significantly more frequent in the group of celiac women with early pregnancy loss (p=0.00003 and 0.028, respectively). Surprisingly, the beta-fibrinogen -455 G>A genotype distribution (but not the allelic frequency of the variant allele) significantly differed between the two groups, since variant genotypes were more frequent in the control group (p=0.009). CONCLUSION: The 4G variant of the PAI-I gene may predispose to miscarriage a subset of celiac women; these data should be verified on larger populations.