Sedimentological features of asbestos cement fragments in coastal environments (Taranto, southern Italy).

Asbestos cement materials (ACMs) are widespread in coastal environments as result of illegal dumping activities. This study focuses on the Taranto area (Italy) in the Mar Grande basin within the northern sector of the Ionian Sea. The complex history of dumping building materials containing high amounts of ACM into the coastal zone, and the erosion, transport and deposition in Marechiaro Bay is a serious environmental hazard. An interdisciplinary research methodology defines the temporal dumping succession, and the erosional processes and phases, the diffusion of ACM, the mineralogical characteristics, and existing physical status of the ACM. A multiscale investigation was conducted. Results show that from 1992 to 2000 a significant increment of dumping operations have occurred. The current cliff has been subject to erosion and redeposition phases, developing a new beach composed of these polluted man-made sediments. The findings persuade the local authorities to close the beach requiring remediation interventions.

A geo-chemo-mechanical study of a highly polluted marine system (Taranto, Italy) for the enhancement of the conceptual site model.

The paper presents the results of the analysis of the geo-chemo-mechanical data gathered through an innovative multidisciplinary investigation campaign in the Mar Piccolo basin, a heavily polluted marine bay aside the town of Taranto (Southern Italy). The basin is part of an area declared at high environmental risk by the Italian government. The cutting-edge approach to the environmental characterization of the site was promoted by the Special Commissioner for urgent measures of reclamation, environmental improvements and redevelopment of Taranto and involved experts from several research fields, who cooperated to gather a new insight into the origin, distribution, mobility and fate of the contaminants within the basin. The investigation campaign was designed to implement advanced research methodologies and testing strategies. Differently from traditional investigation campaigns, aimed solely at the assessment of the contamination state within sediments lying in the top layers, the new campaign provided an interpretation of the geo-chemo-mechanical properties and state of the sediments forming the deposit at the seafloor. The integrated, multidisciplinary and holistic approach, that considered geotechnical engineering, electrical and electronical engineering, geological, sedimentological, mineralogical, hydraulic engineering, hydrological, chemical, geochemical, biological fields, supported a comprehensive understanding of the influence of the contamination on the hydro-mechanical properties of the sediments, which need to be accounted for in the selection and design of the risk mitigation measures. The findings of the research represent the input ingredients of the conceptual model of the site, premise to model the evolutionary contamination scenarios within the basin, of guidance for the environmental risk management. The study testifies the importance of the cooperative approach among researchers of different fields to fulfil the interpretation of complex polluted eco-systems.

Simultaneous antiphospholipid syndrome and heparin-induced thrombocytopenia in a single patient.

Antiphospholipid syndrome and heparin-induced thrombocytopenia are immune-mediated thrombotic conditions initiated by 2 distinct antibodies each targeting a discrete protein-antigen complex. Although produced by 2 different types of antibodies, they are similar in their autoimmune and pathophysiologic mechanisms. We present a case with simultaneous antiphospholipid syndrome and heparin-induced thrombocytopenia syndromes that sheds light on the correlation between these 2 syndromes.

Hypoxia inhibits cyclic nucleotide-stimulated epithelial ion transport: role for nucleotide cyclases as oxygen sensors.

Decreased oxygen delivery to cells (hypoxia) is prevalent in a number of important diseases. Little is known about mechanisms of oxygen sensing at the cellular level or about whether functional correlates of oxygen sensing exist. In this study, we examined the impact of hypoxia on stimulated epithelial ion transport function. T84 cells, a model of intestinal epithelia, were grown on permeable supports, exposed to hypoxia (range 1-21% O2) for periods of time between 0 and 72 h and assessed for stimulated ion transport. Hypoxia evoked a specific decrease in cyclic nucleotide-stimulated (cAMP and cGMP) but not Ca++-stimulated ion transport. 86Rb (K+ tracer) uptake and 125I (Cl- tracer) efflux were reduced in hypoxic cells by >50% and >40%, respectively, fluid movement was reduced by hypoxia (>50% decrease) and reoxygenation resulted in partial recovery of the ion transport responses. Stimulated and basal levels of both cAMP and cGMP were decreased in response to hypoxia, although intracellular ATP levels were unaltered under similar conditions. Exogenous addition of cobalt, nickel or manganese, all of which compete for oxygen binding on heme-containing proteins, mimicked hypoxia. Because guanylate cyclase is a heme protein, we measured the influence of cobalt on activity of guanylate cyclase in purified plasma membrane preparations and found cobalt to inhibit stimulated cGMP levels in this cell-free system. Finally, pharmacological lowering of intracellular cGMP (using LY83583) resulted in decreased cAMP-stimulated Cl- secretion, and direct elevation of cGMP (using 8-bromo-cGMP or dibutyryl-cGMP) restored this hypoxia-induced activity. We conclude that a potential oxygen-sensing mechanism of epithelial cells involves the cooperation of heme-containing proteins such as guanylate cyclase and that biochemical cross-talk between cAMP- and cGMP-stimulated pathways may be important in such responses.

Fluconazole serum concentrations and pharmacokinetics in an obese patient.

Current fluconazole dosing recommendations are based on pharmacokinetic parameters calculated from serum concentration data in subjects and patients of normal weight. These recommendations may be inaccurate when applied to obese individuals due to the physiologic changes of obesity that may influence drug pharmacokinetics. A 39-year-old morbidly obese man (BMI 48.3 kg/m2) was treated with fluconazole 1200 mg/day infused over 6 hours. After 14 days of therapy, blood samples were obtained at 0, 1, 2, 4, 8, 12, 18, and 24 hours after infusion and steady-state serum concentrations were determined using a bioassay. Pharmacokinetic parameters calculated were area under the concentration-time curve (AUC(0-24)) 574.9 mg/L x hour, average steady-state serum concentration 23.9 mg/L, and fluconazole clearance 139.4 ml/minute. Compared with published data, our patient had a lower area under the curve and increased fluconazole clearance. These changes may be due to the drug's increased volume of distribution. Based on these data and the favorable toxicity profile of fluconazole, we recommend considering higher dosages in such morbidly obese patients.

Pinealocyte dense-cored vesicles and synaptic ribbons: a correlative ultrastructural-biochemical investigation in rats and mice.

Dense-cored vesicles (DCV) and synaptic ribbons (SR) were quantified in the pineal gland of the rat (Sprague-Dawley) and mouse (Sasco/ICR strain), and day/night differences in frequency of these organelles correlated with levels of indoles determined by high performance liquid chromatography (HPLC). There were significant day/night differences in levels of serotonin (5HT), 5-hydroxyindole acetic acid (5HIAA), N-acetyl-5HT, and melatonin in the rat gland. Melatonin and N-acetyl-5HT were not detectable in the mouse gland sampled every 4 h over the light:dark cycle. The concentrations of 5HT and 5HIAA (ng/microgram protein) were similar in light-adapted rats and mice, but these indoles did not exhibit a circadian rhythm in the mouse gland. Correlative ultrastructural/biochemical results suggest that DCV do not contain physiologically important stores of 5HT since 1) the mouse gland contains the same number of DCV as the rat during the daytime, but only one-tenth the levels of 5HT, 2) day/night 5HT levels do not vary in the mouse gland, but there is a significant nocturnal decline in DCV numbers, and 3) 5HT levels in the rat gland decline at night when DCV numbers increase. Numbers of SR were significantly elevated at night in the rat and mouse, and the frequency of this organelle was similar in both species. However, ribbon-type SR predominated in rat pinealocytes, whereas SR in the mouse were almost exclusively spherical in shape. Day/night differences in SR numbers in the mouse gland suggest that cellular mechanisms regulating the frequency of this organelle do not involve factors related to indole metabolism. Because of the lack of photoperiodic effects on indole metabolism in the mouse pineal gland, this species is a potentially important model to study the functional relationship of pinealocyte organelles to cyclical changes in pineal products other than indoles (e.g., peptide/protein factors).