Diel observations on populations of Dinophysis and Alexandrium spp. (Dinophyceae) from the NW Adriatic Sea

Quanti-qualitative changes in Dinophysis and Alexatidrium populations from the Gulf of Venice NW Adriatic Sea - were studied on a short time scale (44 h cycles). Under hydrographic conditions of marked thermohaline stratification (July 1995), D. sacculus populations assembled in the surface waters (12 24 yt isopycnals). Division processes took place mostly in the early hours of the morning and at 14:00 h, 4 to 10 % of the population consisted of morphotypes of reduced size (possibly gametes resulting from successive cell divisions). Similar percentages were also observed in October for D. caudata, with a maximum division between 06:00 h and 10:00 h. During this month, coexisting populations of Alexandrium cf. fundyense and A. cf. tamarense displayed rhythmic changes in cell density that slightly differed from those exhibited in July by A. pseudogonyaulax, suggesting a circadian control of the cell cycle rather than a response to hydrographic changes

Diel observations on populations of Dinophysis and Alexandrium spp. (Dinophyceae) from the NW Adriatic Sea

Quanti-qualitative changes in Dinophysis and Alexatidrium populations from the Gulf of Venice NW Adriatic Sea - were studied on a short time scale (44 h cycles). Under hydrographic conditions of marked thermohaline stratification (July 1995), D. sacculus populations assembled in the surface waters (12 24 yt isopycnals). Division processes took place mostly in the early hours of the morning and at 14:00 h, 4 to 10 % of the population consisted of morphotypes of reduced size (possibly gametes resulting from successive cell divisions). Similar percentages were also observed in October for D. caudata, with a maximum division between 06:00 h and 10:00 h. During this month, coexisting populations of Alexandrium cf. fundyense and A. cf. tamarense displayed rhythmic changes in cell density that slightly differed from those exhibited in July by A. pseudogonyaulax, suggesting a circadian control of the cell cycle rather than a response to hydrographic changes

The sxt Gene and Paralytic Shellfish Poisoning Toxins as Markers for the Monitoring of Toxic Alexandrium Species Blooms

Paralytic shellfish poisoning (PSP) is a serious human illness caused by the ingestion of seafood contaminated with saxitoxin and its derivatives (STXs). These toxins are produced by some species of marine dinoflagellates within the genus Alexandrium. In the Mediterranean Sea, toxic Alexandrium spp. blooms, especially of A. minutum, are frequent and intense with negative impact to coastal ecosystem, aquaculture practices and other economic activities. We conducted a large scale study on the sxt gene and toxin distribution and content in toxic dinoflagellate A. minutum of the Mediterranean Sea using both quantitative PCR (qPCR) and HILIC-HRMS techniques. We developed a new qPCR assay for the estimation of the sxtA1 gene copy number in seawater samples during a bloom event in Syracuse Bay (Mediterranean Sea) with an analytical sensitivity of 2.0 × 10° sxtA1 gene copy number per reaction. The linear correlation between sxtA1 gene copy number and microalgal abundance and between the sxtA1 gene and STX content allowed us to rapidly determine the STX-producing cell concentrations of two Alexandrium species in environmental samples. In these samples, the amount of sxtA1 gene was in the range of 1.38 × 105 − 2.55 × 108 copies/L and the STX concentrations ranged from 41−201 nmol/L. This study described a potential PSP scenario in the Mediterranean Sea.Versión del editor5,228

Analisi della biodiversità genetica di alcune specie microalgali responsabili di fioriture tossiche nel Mar Mediterraneo

In this study a genetic diversity of the main Mediterranean dinoflagellate HAB species has been analysed using the phylogeographic based approach. Different microalgal species isolates were characterized by phylogenetic, phylogeographic and population genetic aspects using different molecular markers and genetic analyses.S

The 2-arachidonoylglycerol effect on myosin light chain phosphorylation in human platelets

In human platelets the endocannabinoid 2-arachidonoylglycerol (2-AG) stimulates some important pathways leading to thromboxane B2 formation, calcium intracellular elevation, ATP secretion and actin polymerisation. The aim of the present study was to examine the 2-AG effect on myosin light chain (MLC) phosphorylation and to investigate the mechanisms involved. We demonstrated that 2-AG induced a rapid MLC phosphorylation, stimulating both the RhoA kinase (ROCK) and MLC kinase (MLCK) in a dose and time-dependent manner. In addition MLC phosphorylation was strengthened through the MLC phosphatase inhibition. MLC phosphatase inhibition was accomplished through the RhoA/ROCK and protein kinase C mediated phosphorylation of MLC phosphatase inhibiting subunits MYPT1 and CPI-17. The presence of CB1 receptor in human platelets and the involvement of CB1 receptor in MLC phosphorylation and MLC phosphatase inhibition was shown

The anandamide effect on NO/cGMP pathway in human platelets

In this study the effect of the endocannabinoid anandamide on platelet nitric oxide (NO)/cGMP pathway was investigated. Data report that anandamide in a dose- and time-dependent manner increased NO and cGMP levels and stimulated endothelial nitric oxide synthase (eNOS) activity. These parameters were significantly reduced by LY294002, selective inhibitor of PI3K and by MK2206, specific inhibitor of AKT. Moreover anandamide stimulated both eNOSser1177 and AKTser473 phosphorylation. Finally the anandamide effect on NO and cGMP levels, eNOS and AKT phosphorylation/activation were inhibited by SR141716, specific cannabinoid receptor 1 antagonist, supporting the involvement of anandamide binding to this receptor. Overall data of this report indicate that low concentrations of anandamide, through PI3K/AKT pathway activation, stimulates eNOS activity and increases NO levels in human platelets. In such way anandamide contributes to extend platelet survival

Sjögren’s syndrome associated with antiphospholipid syndrome and fetal myocardial echogenicity: case report

Sjögren’s syndrome is a rare systemic autoimmune disorder associated with pregnancy (0.3-0.6%). The typical occurrence of anti-Ro/SSA and anti-La/SSB autoantibodies in the maternal serum can modify the perinatal outcome: neonatal lupus and congenital heart block are the most common fetal complications. Case: we report a case of pregnancy complicated by a secondary form of SS associated with antiphospholipid syndrome and fetal myocardial echogenicity. Conclusion: in conclusion, increased attention must be paid to pregnancies associated with autoimmune disorders, since careful ultrasonographic and clinical monitoring and preventive treatment with corticosteroids could minimize severe and common fetal complications

Recurrent high-biomass blooms of Alexandrium taylorii (Dinophyceae), a HAB species expanding in the Mediterranean

9 pages, 5 figures, 2 tablesSummer outbreaks of the dinoflagellate Alexandrium taylorii Balech are recurrent events in nearshore waters of Sicily (Italy)—a central region in the Mediterranean Sea—producing dense yellowish-green patches. Beyond the local phenomenon, the problem covers a broader geographic scale, involving also other European localities, mostly in Spain. Biological, environmental, and molecular data are reported here from a semi-closed bay of Sicily (Vulcano Island, Tyrrhenian Sea, 2000-2003), showing in summer the recurrence of high-biomass blooms and events of water discolouration. Without underestimating the setbacks to the tourism industry, the ecological impact of A. taylorii blooms may be important considering the high levels of biomass produced (West Bay, Vulcano: up to a magnitude order of 107 cells l−1, 50-180 μg-Chla l−1, June 2002 and 2003) and coincident conditions of oxygen supersaturation of the waters (130-170%). Trophic trends in the Tyrrhenian site indicate high amounts of nutrients linked to the increased anthropogenic activity in summer, although recently there hasbeen an apparent shift of the marked eutrophic conditions towards a slighter eutrophy. Genetic data on isolates of A. taylorii from the Mediterranean Sea are also discussed. Molecular analyses implied the sequencing of target rDNA regions (5.8S rDNA and ITS regions) of several isolates from different Mediterranean localities, as well as the application of species-specific PCR assays for rapid species identification in preserved field samples. The confirmation of the specific identity provided new insights into the biogeography of this species and further evidence of the occurrence of A. taylorii in a number of Mediterranean localities, both in the western side (the Catalan coast of Spain) and the eastern area (Greece). Analyses of the molecular diversity of geographically distinct isolates of A. taylorii from Italy, Spain, and Greece based on the 5.8S rDNA-ITS region sequences showed a high level of similarity, indicating the existence of an unique Mediterranean populationThis study was supported by the EU project STRATEGY (EVK3-2001-00046)Peer reviewe