Epibiotic ciliates Scyphidia sp. and diatoms on Tigriopus fulvus (Copepoda: Harpacticoida) exoskeleton

Several microorganisms – epibionts – can adhere to living supports taking advantage for their survival, feeding and movement. Epibiosis occurs particularly in aquatic environments, on both benthic and planktonic organisms, among which copepods and cladocerans represent an important living support. The harpacticoid copepod Tigriopus fulvus, living in the splashpools of rocky coasts, was studied to recognize the occurrence of epibionts on the exoskeleton surface using scanning electon microscopy techniques. The first evidence of ciliate Scyphidia sp. on Tigriopus fulvus has been described and the occurrence of algae Cocconeis sp. has been observed as well. Epibionts were found to adhere to antennae, a site linked to the exploitation of water currents carrying food particles to mouthparts and to swimming legs. The reason of the occurrence on swimming legs is less clear and needs further observations. Pertinent results are described and discussed and the influence of epibionts on life cycle and behavior of Tigriopus fulvus is considered

The Mauve Stinger Pelagia noctiluca (Forsskål, 1775). Distribution, Ecology, Toxicity and Epidemiology of Stings. A Review

The toxicity of Cnidaria is a subject of concern due to its influence on humans. In particular, jellyfish blooms can highly affect human economical activities, such as bathing, fishery, tourism, etc., as well as the public health. Stinging structures of Cnidaria (nematocysts) produce remarkable effects on human skin, such as erythema, swelling, burning and vesicles, and at times further severe dermonecrotic, cardio- and neurotoxic effects, which are particularly dangerous in sensitive subjects. In several zones the toxicity of jellyfish is a very important health problem, thus it has stimulated the research on these organisms; to date toxicological research on Cnidarian venoms in the Mediterranean region is not well developed due to the weak poisonousness of venoms of jellyfish and anemones living in this area. In spite of this, during last decades several problems were also caused in the Mediterranean by stinging consequent to Cnidarian blooms mainly caused by Pelagia noctiluca (Forsskål, 1775) which is known to be the most venomous Mediterranean jellyfish. This paper reviews the knowledge on this jellyfish species, particularly considering its occurrence and toxicity

Utilization of Marine Crustaceans as Study Models: A New Approach in Marine Ecotoxicology for European (REACH) Regulation

Pollution problems affect greatly the aquatic environments that are mainly sensitive to several typologies of contamination, such as chemical pollution, oil dumping, microbiological contamination from sewers, etc. To date a lot of chemicals are utilized in productive processes and many new substances are synthesized every year; the utilization and introduction of these newly synthesized chemicals into the environment and in production cycles must be approved after an accurate evaluation of their eventual toxic properties against selected organisms with the main purpose to protect the safety of plants and animals and the human health. These evaluations need to be carried out using test-species which are representative of the environmental compartment under consideration; in this connection, the availability of test-species able to furnish reliable and cheap results and to evaluate the activity of pollutants at the individual and ecosystem level is essential. To date the availability of test-species, easy to collect and to rear, and sensitive to different xenobiotics, is an important aspect in ecotoxicology in order to characterize the risk of chemicals. In the aquatic environment an ideal battery of organisms should comprise the representative links of the food web: a primary producer, such as a microalga, a primary consumer (invertebrate), such as a crustacean, and a secondary consumer (vertebrate), such as a fish. In this connection, the new European regulation REACH (Registration, Evaluation, Authorization of CHemicals) n. 1907/2006 introduces an integrated system for the management of all produced/imported chemicals for an amount \ub31 ton/year and states that all substances destined to be used in the EU and to be introduced into the production processes must be subject to accurate evaluation including toxicity tests on selected organisms. All tests indicated by REACH must be carried out in conformity with well defined analysis methods determined by the EU or, failing that, according to the OECD guidelines or to other determined methods. Furthermore, all tests must be performed in conformity with the principles of Good Laboratory Practice (GLP) according to the pertinent Community directive

Gluten sensitivity and neurological manifestations

The authors report on six cases of gluten-sensitivity, also defined non-celiac gluten sensitivity, characterized by abdominal features (diarrhea, bloating, pain), genetic positivity for predisposition to celiac disease (DQB1* 02 in all cases; DQA1*05 in three; DQA1*02 in two, DQB1*03 in two), negative anti-t-Transglutaminase antibodies, normal mucosa on biopsy in four cases, type 1 of Marsh in one case. The subjects presented frequent central nervous system (CNS) symptoms: headache in three patients, somnolence in one, electroencephalogram aspecific alterations in three (in two of them with previous seizures), leptomeningeal cyst in one, intracranial calcification in one, cerebral gliosis in two. After a gluten-free diet, all intestinal and clinical CNS features remitted, but re-appeared after gluten reintroduction. On the basis of the neurological signs, the authors stress the relevance of immune innate system in the pathogenesis of these cases with possible subsequent evolution on immune adaptive system involvement

The venom and the toxicity of Pelagia noctiluca (Cnidaria: Scyphozoa). A review of three decades of research in Italian laboratories and future perspectives

Recurrent outbreaks of Pelagia noctiluca and health problems consequent to stings were recorded during the last decades. This phenomenon forced some Italian University laboratories to study this cnidarian. The first studies concerned the distribution, biochemical composition and morphology of nematocysts of Pelagia noctiluca. The discharge mechanism of nematocysts was defined starting from early 1980s when enzymes, cations, anions, and pH were observed to have an influence on this process. Notably, trypsin, extreme pH values, some anions (I–, Cl–, SCN–), and thioglycolate were seen to induce, while La3+ and Gd3+ to prevent, nematocyst discharge. The discharge of both in situ and isolated nematocyst was found to be Ca2+ dependent. Furthermore, Pelagia noctiluca nematocysts were seen to retain their discharging capacity in distilled water. The toxicological evaluations were carried out mainly using the crude venom from Pelagia noctiluca because, unfortunately, to date the composition of venom remains unknown. Hemolytic and cytotoxic properties of crude venom have been evaluated on erythrocytes and cultured guinea-pig fibroblasts, mouse fibroblasts, and cancer (neuroblastoma) cells. The activity of Pelagia noctiluca venom on other cnidarians has been also assessed. The crude venom induced apoptosis by reactive oxygen species generation and decrease in mitochondrial transmembrane potential, loss of mitochondrial integrity, and alteration of cell membrane permeability. A pore-forming action mechanism on mitochondrial membrane with oxidative damage was also suggested. The protective activity of some compounds against envenomations has been also evaluated. Future challenges will concern the attempts to characterize the venom and to perform a wider screening of cytotoxicity induced to normal and cancer cells

Impact of synthetic surfactants and oil dispersants on the gills of juvenile gilthead (Sparus aurata L.)

Histological, scanning electron microscopic and immunohistochemical studies were performed on the gills of juvenile gilthead (Sparus aurata L.) exposed to various concentrations of three anionic detergents: sodium dodecyl sulphate (SDS), safety sea cleaner 2 (SSC2), and FINASOL OSR2, in short term (96 h) and chronic (28 days) experiments. The mortality rate, median lethal concentration (LC50) and the no observed effect concentration (NOEC), were calculated. At concentrations above 10 mg/L, mortality was from 50 to 100% after exposure to SDS and SSC2, both in short term and chronic experiments. Gills were spongiotic and there were many lamellar fusions, membrane disruptions, hydropic degenerations and exfoliations of lamellar and interlamellar epithelium after 96 h of treatment and more markedly after chronic experiment. Microridges of the cell surface were less evident or absent. The enzymes of ion transport were down regulated. Exposure to FINASOL OSR2 (100 mg/L) showed no evident branchial alteration

Chiari I malformation, syringomyelia and papilledema: a malformative complex connected to oculo-auriculo-vertebral spectrum

The authors discuss the association of papilledema with Chiari I malformation (CMI) and syringomyelia on the basis of a clinical case studied by radiology, immunology and biochemistry methods. In the presence of normal haematology, blood immunology and biochemistry, clinical signs of headache and papilledema associated to hemifacial asymmetry, blind neck fistulas, malformed ears and spinal abnormalities (symptoms of oculo-auricolo- vertebral spectrum - OAVS), were observed. Magnetic resonance images and computed tomography demonstrated the occurrence of lowered cerebellar tonsils, but with values lower than those typical of the CMI syndrome and syringomyelia. The authors concluded for a minor form (benign ectopia) in the CMI syndrome, associated to papilledema and syringomyelia, and hypothesize an unique pathogenetic mechanism for this complex, connected to neural crest cell development and to OAVS, as extension of this spectrum. The authors underline the relevance of the facial/neck lateral signs for the diagnosis of OAVS associated to brain stem pathology and CMI

Oculo-auriculo-vertebral spectrum associated to progressive external ophthalmoplegia. Biological, laboratory, electrophysiological and clinical aspects

The authors discuss about the relationships between oculoauriculo- vertebral spectrum (OAVS), a malformative condition affecting eyes, ears and vertebral structures mainly derived from neural crests, and autosomal dominant progressive external ophthalmoplegia (adPEO) – an electron transport chain disorder characterized by palpebral ptosis and muscular symptoms – on the basis of laboratory data and clinical signs in a case belonging to a family in which symptoms of both diseases occur. Hemifacial microsomia and ears abnormalities were the main neural crest cells (NCC) derived signs for OAVS diagnosis. Palpebral ptosis and the associated hyperlactacidemia with high Lactate to Pyruvate ratio were main signs for the suspicion of adPEO, but the diagnosis was proposed by clinical, biochemical, electrophysiological and genetic methods because the biopsy not always is diagnostic, as in our case. The association of two groups of symptoms (malformed, NCCrelated, and myopatic-electron transport related) in the same subject as observed in our case and partially in the family, may be ascribed to nuclear abnormalities and mitochondrial electron transport disorder, respectively, as well as to a possible common etiopathogenetic mechanism. In some cases of OAVS, the malformations may be consequent to oxidative phosphorilation disease (OXPHOS) derangement, as previously demonstrated; the extensive determination of lactacidemia may be important to address the research on OAVS patients in the mitochondrial/OXPHOS genetic domain, with advantage in the knowledge of OAVS pathogenesis

Mediterranean Jellyfish Venoms: A Review on Scyphomedusae

The production of natural toxins is an interesting aspect, which characterizes the physiology and the ecology of a number of marine species that use them for defence/offence purposes. Cnidarians are of particular concern from this point of view; their venoms are contained in specialized structures–the nematocysts–which, after mechanical or chemical stimulation, inject the venom in the prey or in the attacker. Cnidarian stinging is a serious health problem for humans in the zones where extremely venomous jellyfish or anemones are common, such as in temperate and tropical oceanic waters and particularly along several Pacific coasts, and severe cases of envenomation, including also lethal cases mainly induced by cubomedusae, were reported. On the contrary, in the Mediterranean region the problem of jellyfish stings is quite modest, even though they can have anyhow an impact on public health and be of importance from the ecological and economic point of view owing to the implications on ecosystems and on some human activities such as tourism, bathing and fishing. This paper reviews the knowledge about the various aspects related to the occurrence and the stinging of the Mediterranean scyphozoan jellyfish as well as the activity of their venoms

Diterpenoids in marine Cnidaria: an overview of existing data.

Cnidarians are venomous animals widely distributed in all marine environments. Venomousness is a primary feature of these organisms, which is especially notable for some species that are considered to be a threat to humans and a serious hindrance for economic activities such as tourism and fishing. In spite of this, cnidarians are also an important source of compounds having useful properties, although relevant research is still in its infancy. Diterpenoid compounds isolated from some cnidarians, mainly benthic species (soft corals), have been demonstrated to have antimicrobial, antimalarial, antifungal, and antiviral properties. Other cnidarian-derived diterpenoids have been shown to have hemolytic properties on mammal erythrocytes. Furthermore, the cytotoxicity of diperpenoids from cnidarians has been evaluated and demonstrated on leukemic, colorectal, and other cancer cells. Therefore, cnidarians can be considered a promising source of such interesting compounds, and diterpenoid compounds derived from cnidarian extracts may prove useful as new drugs. This review aims to describe and discuss the available data on discovery and usefulness of cnidarian diterpenoids