Global warming-related response after bacterial challenge in Astroides calycularis, a Mediterranean thermophilic coral.

A worldwide increase in the prevalence of coral diseases and mortality has been linked to ocean warming due to changes in coral-associated bacterial communities, pathogen virulence, and immune system function. In the Mediterranean basin, the worrying upward temperature trend has already caused recurrent mass mortality events in recent decades. To evaluate how elevated seawater temperatures affect the immune response of a thermophilic coral species, colonies of Astroides calycularis were exposed to environmental (23 °C) or elevated (28 °C) temperatures, and subsequently challenged with bacterial lipopolysaccharides (LPS). Using immunolabeling with specific antibodies, we detected the production of Toll-like receptor 4 (TLR4) and nuclear factor kappa B (NF-kB), molecules involved in coral immune responses, and heat shock protein 70 (HSP70) activity, involved in general responses to thermal stress. A histological approach allowed us to characterize the tissue sites of activation (epithelium and/or gastroderm) under different experimental conditions. The activity patterns of the examined markers after 6 h of LPS stimulation revealed an up-modulation at environmental temperature. Under warmer conditions plus LPS-challenge, TLR4-NF-kB activation was almost completely suppressed, while constituent elevated values were recorded under thermal stress only. An HSP70 up-regulation appeared in both treatments at elevated temperature, with a significantly higher activation in LPS-challenge colonies. Such an approach is useful for further understanding the molecular pathogen-defense mechanisms in corals in order to disentangle the complex interactive effects on the health of these ecologically relevant organisms related to global climate change.

Bi- and three-dimensional fractal analysis of the brown seaweed Gongolaria montagnei and their relationship with gastropod molluscs assemblage.

Habitat complexity is one of the main influences on biodiversity in marine environments, particularly in coastal areas where foundation seaweeds provide substrate for highly diverse communities. We studied the 2D and 3D fractal dimensions of Gongolaria montagnei (Fucales) over the vegetative season and examine their relationship with the abundance, species richness and morpho-functional groups of the gastropod associated. Overall, the 3D fractal analysis method used here better describes seaweeds structural complexity compared to the traditional 2D fractal analysis, as highlighted by the higher relationship with gastropod assemblage associated to the alga in terms of abundance, number of species and morpho-functional groups. We propose this new method as a valuable tool for understanding the relationship between seaweeds and associated fauna, which is critical for gaining a better understanding of the role that algal species play in a specific habitat and the consequences of their loss.

Biogenic habitat shifts under long-term ocean acidification show nonlinear community responses and unbalanced functions of associated invertebrates.

Experiments have shown that increasing dissolved CO2 concentrations (i.e. Ocean Acidification, OA) in marine ecosystems may act as nutrient for primary producers (e.g. fleshy algae) or a stressor for calcifying species (e.g., coralline algae, corals, molluscs). For the first time, rapid habitat dominance shifts and altered competitive replacement from a reef-forming to a non-reef-forming biogenic habitat were documented over one-year exposure to low pH/high CO2 through a transplant experiment off Vulcano Island CO2 seeps (NE Sicily, Italy). Ocean acidification decreased vermetid reefs complexity via a reduction in the reef-building species density, boosted canopy macroalgae and led to changes in composition, structure and functional diversity of the associated benthic assemblages. OA effects on invertebrate richness and abundance were nonlinear, being maximal at intermediate complexity levels of vermetid reefs and canopy forming algae. Abundance of higher order consumers (e.g. carnivores, suspension feeders) decreased under elevated CO2 levels. Herbivores were non-linearly related to OA conditions, with increasing competitive release only of minor intertidal grazers (e.g. amphipods) under elevated CO2 levels. Our results support the dual role of CO2 (as a stressor and as a resource) in disrupting the state of rocky shore communities, and raise specific concerns about the future of intertidal reef ecosystem under increasing CO2 emissions. We contribute to inform predictions of the complex and nonlinear community effects of OA on biogenic habitats, but at the same time encourage the use of multiple natural CO2 gradients in providing quantitative data on changing community responses to long-term CO2 exposure.

Laminar field potentials and unit activity in the cortex during visual evoked potentials in feline generalized penicillin epilepsy.

Modifications of the visual evoked potential during generalized epilepsy were investigated in feline generalized penicillin epilepsy. Visual evoked potentials and their intracortical profiles were averaged during intraburst periods and during the wave of the spike and wave complex to a fixed latency from the preceding spike. During interburst periods, the evoked potentials showed an increase in the amplitude of the early positive peak and the appearance after a variable latency period of a second consistent peak during the late phase of the evoked potential. Laminar profiles of visual evoked potentials and their current source density analysis compared with the activity of single cortical units suggested an early excitation of neuronal populations at layers II, III and IV, as seen before penicillin, followed by a variable inhibitory period and by a subsequent rebounded excitation at those same levels. In evoked potentials recorded during the wave of the spike and wave complex, the early phase was unchanged and the late positive peak and the corresponding deep sink were greatly reduced or nonexistent, although the rebounded activation of cortical units was still evident. These data support the conclusion that during feline generalized penicillin epilepsy a larger number of cortical neurons are activated and a sequence of excitation-inhibition-excitation, probably involving also subcortical structures, is brought about. Moreover, the inhibitory phase of the spike and wave complex is soon disrupted whenever a consistent sensory stimulus arrives at the cortex.

[Effects of phosphatidylserine in an experimental model of generalized epilepsy]. / Effetti della fosfatidilserina in un modello sperimentale di epilessia generalizzata.

The possible antiepileptic activity of PS has been tested in a model of generalized epilepsy induced by penicillin in the cat. In acute experiments, topical application to the cortex of PS (from 20 mg/ml to 50 mg/ml) produced a reverse in the polarity of the spike and wave complex and, sometimes, a decrease in the voltage as well as a morphological deformation of s-w bursts. Chronic intraperitoneal administration of PS induced a decrease of the epileptic burst frequency. The effect was already apparent after 14 days and of greater extent after 21 days. Finally the antiepileptic effect of 0,2-0,5 mg/Kg diazepam, given in a single dose during the maximal epileptic activity resulted markedly reinforced in animals chronically treated with PS.

[Primidone kinetics and analysis of its interactions with the major antiepileptic drugs]. / Studio della cinetica del primidone e analisi delle sue interazioni con farmaci antiepilettici maggiori.

In 5 volunteers, after single oral administration of 10 mg/Kg of primidone (PRM) plasmatic concentration of the drug has been monitored during 24 hours. PRM plasma half life was found longer than in previous reports. It was however confirmed that its metabolite phenobarbital (PB) is not present in the blood for at least 48 hours. Moreover 166 patients under long term PRM treatment were investigated as to the influence of phenytoin (DPH) and carbamazepine (CBZ) on the PB serum levels. It was found that patients in therapy with PRM + DPH showed a better relationship between PRM oral dose and PB plasma level and also between oral dose and plasma level of DPH than in patients in monotherapy with PRM or DPH, whereas these effects were not evident in patients taking PB + DPH.

Feline generalized epilepsy induced by tranexamic acid (AMCA).

Epileptic activities induced by topical application of tranexamic acid (AMCA) and penicillin to the cortex of 12 cats in acute experiments were compared. Both substances when diffusely applied on a wide cortical area of both hemispheres at very low concentration produced an EEG pattern consisting of spike-wave bursts similar to the electrographic manifestations seen in feline generalized epilepsy induced by large parenteral doses of sodium penicillin. These epileptic bursts could be triggered by repetitive stimulation of nucleus centralis medialis. Increased concentrations of both AMCA and penicillin led to the appearance of bilaterally synchronous spikes and poly-spikes which were not further excited by NCM stimulation. Two factors seem to play an important role in eliciting spike-wave bursts in both models: (1) the area of the cortex exposed to the epileptogenic agent and (2) the concentration of the epileptogenic agent used. The similar effects observed in 5 chronic animals either by intravenous injection of high doses of AMCA or by intramuscular injection of sodium penicillin confirm the results obtained in acute experiments and suggest a new way of inducing feline generalized epilepsy.

[Effect of gamma-amino-beta-hydroxybutyric acid (GABHB) on experimentally-induced epileptic activity]. / Effetti dell'acido gamma-amino-beta-idrossibutirrico (GABOB) su attività epilettiche sperimentalmente indotte.

Effects of GABOB on experimental induced epileptiform activities. Antiepileptic activity of gamma-amino-beta-hydroxybutyric acid (GABOB) has been tested on different models of either generalized or focal epilepsy induced by penicillin in cat. In acute experiments, topical application to the cortex of GABOB (from 1% to 10%) during feline generalized epilepsy produced a reverse in polarity of the spike and wave complex, while in the so called "epileptogenic corticopathy" it induced a decrease in voltage as well as in frequency of the bilateral spikes and polyspikes. A similar effect was seen after parenteral injection of GABOB in acute preparations in which a penicillin focus was created. In chronic animals, in which feline generalized penicillin epilepsy had been produced, a single i.v. injection of GABOB induced a significant decrease of the epileptic bursts during the first 30' after the antiepileptic drug was injected. Finally in 4 animals chronic administration of GABOB leaded to a mean decrease of the epileptic bursts higher than 50%. These data support the antiepileptic activity of GABOB. However the high doses used in this study to achieve the antiepileptic effect could make difficult its use in human patients.

[Use of substances modifying serotonin metabolism in the treatment of narco-cataplexy (considerations on 5 cases)]. / L'uso di sostanze modificanti il metabolismo della serotonina nel trattamento della narco-cataplessia (considerazioni su 5 casi).

The AA., after a critical analysis of the new proposed treatments for the narco-cataplexy, report their experience about the therapeutic possibilities of this syndrome with particular manipulations of cerebral serotonin (5-HT). In 5 patients they tried to act on the two sides of the sleeping-waking cycle by using a diurnal administration of Methysergide (5-HT inhibitor) and an evening loading of L-Tryptophan combined with Benserazide (dopa-decarboxilase inhibitor). The immediate and long term results on the nercoleptic as well as cataplectic symptoms can be considered good. Conversely treatments with Clomipramine alone exerted poor beneficial effects in these patients. The AA. discuss the physiopathogenetic mechanisms which are thought to be involved in this disease.