Warming and Inhibition of Salinization at the Ocean's Surface by Cyanobacteria.

This paper describes high-resolution in situ observations of temperature and, for the first time, of salinity in the uppermost skin layer of the ocean, including the influence of large surface blooms of cyanobacteria on those skin properties. In the presence of the blooms, large anomalies of skin temperature and salinity of 0.95°C and -0.49 practical salinity unit were found, but a substantially cooler (-0.22°C) and saltier skin layer (0.19 practical salinity unit) was found in the absence of surface blooms. The results suggest that biologically controlled warming and inhibition of salinization of the ocean's surface occur. Less saline skin layers form during precipitation, but our observations also show that surface blooms of Trichodesmium sp. inhibit evaporation decreasing the salinity at the ocean's surface. This study has important implications in the assessment of precipitation over the ocean using remotely sensed salinity, but also for a better understanding of heat exchange and the hydrologic cycle on a regional scale.

Polycyclic aromatic hydrocarbons in Laurus nobilis leaves as a measure of air pollution in urban and rural sites of Tuscany.

The levels of 9 polycyclic aromatic hydrocarbons (PAHs) 6 of which carcinogenic were measured in the leaves of evergreen tree (Laurus nobilis) sampled in 13 locations in summer and winter in Tuscany, Italy. The carcinogenic PAH levels were correlated with the PAH air levels sampled at the same site. Samples from larger towns had higher PAH levels than those from medium and small towns. Leaves collected in the center of larger cities had higher carcinogenic PAH levels than samples from residential areas indicating that vehicular traffic is the main PAH source. Carcinogenic PAH levels in leaves collected in the winter in medium towns were considerably higher than expected, probably due to domestic heating. These findings demonstrate that air quality in terms of PAH contamination is not markedly different in towns of different size in Tuscany.

Sudden dilatation of right ventricle in two patients with thrombosis of a mitral Björk valve detected by echocardiography: different aspects of acute and chronic overloads of the right ventricle in these patients.

Acute thrombotic obstruction of disc valve prosthesis is a rare but catastrophic event without an immediate correct diagnosis and precocious treatment (Amman et al., 1984; Assanelli et al., 1986; Copans et al., 1980; Mann et al., 1986; Gibson et al., 1974; Johnson et al., 1973; Ledain et al., 1986). That is the main reason it is important to consider each helpful sign in order to recognize such a situation. We detected an important dilatation of the right ventricle in two patients with different stages of thrombosis of mitral Björk, the first one had also a chronic dilatation of the right ventricle due to tricuspid regurgitation. The clinical and pathophysiological aspects of these unusual situations are described in this article.

Invasive and echocardiographic evaluation of non-Q myocardial infarction with isolated stenosis of descending anterior coronary artery.

Prognostic and clinical characteristics of acute myocardial infarction (AMI) can usually justify surgical and/or angioplastic approach if the residual ventricular function is still good. Multivessel disease frequently complicates results interpretation. We studied with 2D echocardiography and coronary angiography two groups of patients with one vessel stenosis located on anterior descending (AD) and previous AMI (means 19 days): 23 patients with spontaneous non-Q infarction (group 1), and 23 patients with Q infarction. Left ventricular function was better in group 1. Percent occlusion of AD was lower in group 1 and angiographic AD caliber was significantly higher. Differences between groups were much more evident in subgroups with proximal stenosis of AD: patients of non-Q subgroups had very good left ventricular function but frequently had post-AMI instable angina (88%). Our results underline the usefulness of aggressive diagnostic and therapeutic approach in non-Q AMI, because of higher amount of myocardium at risk.

Accuracy of field spectrometry in estimating 137Cs contamination in high altitude alpine soils.

In situ gamma ray spectrometry is an attractive method for providing information on the concentrations of radionuclides in the soil. This method requires separate knowledge of the soil density and of the radioactivity distribution relative to soil depth. In-field gamma spectrometry measurements were performed together with sampling of the soil at the same site for subsequent gamma spectrometry analysis in the laboratory. Results of 137Cs concentration were compared in order to: (i) verify the effectiveness of in situ gamma spectrometry in averaging local inhomogeneties in the soil; and (ii) quantify the sensitivity of the gamma ray spectrometry soil radioactivity evaluation with respect to the variability of the depth profiles obtained from a single site sampling. The site of study is a high altitude pasture, in the Alpine environment.

[Levels of polycyclic aromatic hydrocarbons (PAHs) in air samples in the city of Arezzo (1997-1998)]. / Livelli aerei di idrocarburi policiclici aromatici (IPA) nella città di Arezzo (1997-1998).

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed environment pollutants of air, water and soil. Since many PAHs are potent mutagens and/or carcinogens the occurrence of these compounds in the lower atmosphere is an important element of environmental pollution. We measured PAH levels in airborne particles collected in the town of Arezzo, (Tuscany, Italy), during the period April 1997-February 1998. Air monitoring for 24 h was repeated for 7 days, during two weeks, in each season; a total of 84 air samples were obtained sampling two urban sites where the traffic is the main source of pollution. One site is a residential area. The data of this study indicate a pronounced seasonal variation in PAH levels and show that in cold spells other sources of contamination besides vehicular traffic are important.

[Thromboembolus migrating into the right heart in pulmonary embolism. Echocardiographic and clinico-therapeutic aspects in 7 cases and review of the literature]. / Tromboembolo migrante nelle cavità cardiache destre in corso di embolia polmonare. Aspetti ecocardiografici e clinico-terapeutici su 7 casi e revisione della letteratura.

We report the clinical, echocardiographic and therapeutic aspects and the evolution of 7 cases of right cardiac migrant thromboembolus in pulmonary embolism (5 M and 2 F, aged 43 to 91). Our data are also compared with all the cases reported in the literature (77 patients). During a sample year (1987) we systematically performed two-dimensional echocardiograms (2D Echo) as early as possible in all the patients admitted to our Coronary Care Unit for suspected pulmonary embolism; among 42 patients the diagnosis of pulmonary embolism was confirmed in 30 out of 42 patients. A relatively high incidence of thromboembolus was found (5/30, 17% in 1987); this finding seems to be relative to the early execution of the 2D Echo study (thromboembolus was found in 4/5 patients when 2D Echo was performed within 20 hours and in only 1/23 when 2D Echo was performed later). The 2D Echo was always evocative of freely floating migrant thromboembolus (6 in right atrium, 1 in right ventricle) and no differential diagnosis with thrombi in situ or other masses was necessary. The therapy for 6 patients hospitalized for pulmonary embolism and surviving the first hours (1 patient died immediately) was: surgical in 1 case, medical in the other 5. Medical therapy consisted only of heparin-calcium in one patient and heparin-calcium + dipyridamole in another because of contra-indications for more aggressive therapy. One patient underwent anticoagulant therapy with i.v. heparin. The remaining two underwent fibrinolytic therapy with urokinase and, afterwards, anticoagulant therapy: in 1 case the therapy was started after the embolization of the mass in the pulmonary artery had occurred; in the other one we observed the progressive reduction of thromboembolus until its disappearance within 5 days without any signs of further embolization. All patients survived and were discharged within 25 days, despite the occurrence of lung embolization in 4 of them. The review of 77 cases reported in the literature shows good outcomes for embolectomy when compared with medical therapy, but almost half of the patients underwent surgical therapy directly. Medical therapy experience, particularly with thrombolytic agents (10 cases in all), is still too scarce to exclude its role, as indeed our experience seems to indicate.

[Echocardiographic and cardioangiographic evaluation of non-Q infarction with isolated stenosis of the anterior descending artery]. / Valutazione ecocardiografica e cardioangiografica dell'infarto non Q con stenosi isolata dell'arteria discendente anteriore.

We studied with two-dimensional echocardiography and coronary angiography 2 groups of patients with one-vessel stenosis located on anterior descending (IVA) and previous acute myocardial infarction (AMI; means 19 days): 23 patients with spontaneous non-Q infarction (Group I), and 23 patients with Q infarction (Group II). Left ventricular function was better in Group I (echo score: 2.04 +/- 2.64, angiographic ejection fraction: 65.65 +/- 9.7 in Group I, echo score: 4.78 +/- 3.14, angiographic ejection fraction: 49.47 +/- 9.1 in Group II, p less than 0.001). Percent occlusion of IVA was lower in Group I and angiographic IVA caliper was significantly higher (p less than 0.05). Differences between groups were much more evident in subgroups with proximal stenosis of IVA: patients of non-Q subgroup had very good left ventricular function but frequently had post-IMA unstable angina (78%). Our results underline usefulness of aggressive diagnostic and therapeutic approach in non-Q AMI, because of higher amount of myocardial a risk.