Effects of biological factors and seasonality on the level of polycyclic aromatic hydrocarbons in red mullet (Mullus barbatus).

This study evaluates the effects of biological factors of fish and seasonality on Polycyclic Aromatic Hydrocarbon (PAH) accumulation in red mullet (Mullus barbatus) tissue. Specimens were collected monthly with a bottom trawl net in an offshore fishing ground in the Northern and Central Adriatic Sea (Geographical Sub Area 17) throughout 2016. The edible fillets of 380 individuals were analyzed for the concentrations of individual PAH, total PAH, and low, medium and high molecular weight (MW) PAHs. PAH bioaccumulation was related to their physicochemical characteristics (MW, and logarithm of the octanol-water partition coefficient, log Kow), some biological parameters of fish (body size, age, sex, reproductive stage and total lipid content), and catch season. The PAH bioaccumulation pattern and the effects of the different factors varied according to PAH MW. The heavier (medium and high MW) PAHs showed higher levels in winter-autumn and in pre-spawners compared with spawners and post-spawners. Our findings suggest that an important detoxification mechanism, albeit limited to the heavier PAHs, acts in the spawning and post-spawning stage. Low MW PAHs appeared to be unaffected by reproductive stage, lipid content and seasonality. Reproductive stage and seasonality seem to play an important role in the accumulation of heavier PAH, whereas total lipid content and age seem to exert a limited influence, and body size no effect at all.

Angiographic presentation of coronary artery spasm in heart transplant recipients.

We describe the angiographic characteristics of coronary artery spasm observed in 12 out of 247 (4.9%) patients who underwent 808 coronary angiographies after heart transplantation. Coronary artery spasm was diagnosed when localized and reversible narrowing of the coronary lumen was identified. After coronary artery spasm identification all patients were followed-up clinically for a mean period of 5.1 years. Coronary artery spasm was documented 1-3 years after heart transplant. Coronary artery spasm affected 1 main coronary artery in 10 patients and 2 in 2 patients; in 3 patients 1 or more secondary branches were also affected. The right coronary artery was affected by coronary artery spasm in 8 patients and the anterior descending coronary artery in 6 patients. In 6 patients coronary artery spasm was mechanically induced by the catheter tip. The degree of luminal narrowing due to coronary artery spasm ranged from mild to almost complete occlusion. Coronary artery spasm appeared as a single tubular smooth and concentric stenosis in 8 patients, was discrete in 2 patients and multiple on the same vessel in 2 patients. In 1 patient coronary artery spasm was erroneously interpreted as an organic lesion and percutaneous transluminal coronary angioplasty was planned. During follow-up 3 patients out of 4 who had shown multiple coronary artery spasm died and 2 patients developed critical organic stenosis. In conclusion coronary artery spasm after heart transplant is less rare than commonly believed. Although it usually has a peculiar appearance, it can be misinterpreted as an organic lesion. Multiple coronary artery spasm appears to carry a poor prognosis.

Myocardial region (right or left ventricle) and aetiology of heart failure can influence the inotropic effect of ouabain in failing human myocardium.

AIMS: To investigate whether the inotropic effect of ouabain in failing human myocardium varies according to the heart chamber tested (right or left ventricle) or the aetiology of the heart disease, i.e. ischaemic or idiopathic. METHODS: The inotropic effect of ouabain was measured, as the percentage change in baseline tension, in myocardial strips isolated from right (RV; n=21) and left ventricles (LV; n=21) of hearts explanted from patients with idiopathic (IDC; n=11) and ischaemic cardiomyopathy (CAD; n=10). Concentration-effect curves obtained with ouabain (0.05-1.6 micromol l-1 ) were analysed using the Emax sigmoidal model, and the following parameters were calculated: Emax, EC50, n and EC10 (threshold concentration). The influence of ventricular chamber and heart failure aetiology on these parameters was evaluated by means of a two-way anova. RESULTS: Age and baseline haemodynamic parameters did not differ between IDC and CAD patients. Baseline strip contractility was highly variable (range: 0.48-10.0 mN), but neither ventricular chamber nor aetiology could explain such variability. A two-way anova showed that EC10 was greater in CAD than in IDC preparations (0.097+/-0.013 micromol l-1 vs 0.059+/-0. 009 micromol l-1; 95% C.I. for difference 0.043, 0.071) and Emax was lower in RV than in LV (121+/-21% vs 250+/-38%; 95% C.I. -221, -36), while EC50 and n were not significantly different between groups. CONCLUSIONS: The inotropic effect of ouabain in human myocardium may vary according to aetiology of heart failure and the ventricle being tested. Although our results do not support the hypothesis of increased sensitivity to cardiac glycosides in CAD patients, they may explain the diminished effect observed in patients with RV failure.

Evaluation of the regional responsivity to ryanodine of human myocardium from patients with idiopathic dilated cardiomyopathy and secondary cardiomyopathies.

The aim of the study was to compare the contractile response to ryanodine of human heart preparations taken from right and left ventricles of patients affected by idiopathic (IDCM) and secondary (SCM) end-stage dilated cardiomyopathies. Right and left ventricle myocardial strips were obtained from hearts of patients undergoing orthotopic heart transplantation and suspended in an oxygenated bath (T = 35 degrees C; stimulation frequency = 0.5 Hz). After an equilibration period, a cumulative dose-response curve for contractility (peak tension) was obtained with ryanodine (0.5, 1, 2, 4, 8, 16, 32, 64 microM). Basal contractility was not significantly different between right and left ventricles or between IDCM and SCM preparations. Ryanodine reduced peak myocardial tension but failed to completely suppress it, even at concentrations which achieved maximum effect. Ryanodine effect still persisted after a 45'-60' washout. The concentration-effect curves from IDCM right ventricle, IDCM left ventricle, SCM right ventricle and SCM left ventricle were compared: IDCM left ventricle was less sensitive to ryanodine than IDCM right ventricle and SCM left ventricle, while no difference was detectable between SCM left ventricle and SCM right ventricle. Thus, the overall sensitivity ranking was: IDCM left ventricle < IDCM right ventricle = SCM right ventricle = SCM left ventricle. IDCM left ventricle showed, in addition, a biphasic response with a shift from negative to positive inotropic effect at concentrations higher than approximately 10 microM. These findings indicate that the cardio-depressant effect of ryanodine, a drug which interferes with intracellular Ca release from the sarcoplasmic reticulum, differs quantitatively and qualitatively in IDCM left ventricle from both IDCM right ventricle and SCM left ventricle. This suggests that some specific alteration in the intracellular Ca signalling in IDCM exists and, from a methodological point of view, stresses the need for a "bi-ventricular" approach to studying biochemical and functional abnormalities of advanced congestive heart failure.