In memory of Prof. Massimo Cocchi, past president and honorary president of the Italian Society for Experimental Biology (Società Italiana di Biologia Sperimentale - SIBS)

Prof. Massimo Cocchi, one of the most experienced scientists in nutritional biochemistry, past and honorary President of the Italian Society for Experimental Biology (Società Italiana di Biologia Sperimentale), passed away on May 19th, 2022, in his house in San Lazzaro di Savena (Bologna). He was a man of the highest value both from the scientific and from the human point of view. He was a landmark for a lot of students, as well as for his friends and colleagues who always appreciated his high moral standing and his immeasurable competence not only in the scientific field which was the subject of his work during all life, but also in many other fields of biology and medicine, so that anyone who met him could always receive a suggestion or a reliable scientific opinion. [...]

Role of model organisms and nanocompounds in human health risk assessment

Safeguarding the environment is one of the most serious modern challenges, as increasing amounts of chemical compounds are produced and released into the environment, causing a serious threat to the future health of the Earth as well as organisms and humans on a global scale. Ecotoxicology is an integrative science involving different physical, chemical, biological, and social aspects concerned with the study of toxic effects caused by natural or synthetic pollutants on any constituents of ecosystems, including animals (including humans), plants, or microorganisms, in an integral context. In recent decades, this science has undergone considerable development by addressing environmental risk assessments through the biomonitoring of indicator species using biomarkers, model organisms, and nanocompounds in toxicological assays. Since a single taxon cannot be representative of complex ecotoxicological effects and mechanisms of action of a chemical, the use of test batteries is widely accepted in ecotoxicology. Test batteries include properly chosen organisms that are easy to breed, adapt easily to laboratory conditions, and are representative of the environmental compartment under consideration. One of the main issues of toxicological and ecotoxicological research is to gain a deeper understanding of how data should be obtained through laboratory and field approaches using experimental models and how they could be extrapolated to humans. There is a tendency to replace animal tests with in vitro systems and to perform them according to standardized analytical methods and the rules of the so-called good laboratory practice (GLP). This paper aims to review this topic to stimulate both efforts to understand the toxicological and ecotoxicological properties of natural and synthetic chemicals and the possible use of such data for application to humans.

Inhibitory effect of plant extracts on the cytotoxicity of eurytele nematocysts from <em>Pelagia noctiluca</em>

Some species of Cnidarians, well known venomous organisms, are able to induce serious health problems as well as economic and social trouble. A lot of data show that cnidarian venoms can be cytotoxic to cultured cells. Therefore, a priority of the research is to find tools which could counteract the damaging activity of venoms. In this connection, the modulatory effects exerted by extracts of plants Ananas comosus (L.) and Carica papaya (L.) on cytotoxicity of heterotrichous microbasic eurytele nematocysts isolated from the jellyfish Pelagia noctiluca was evaluated. The nematocyst extract induced strong cytotoxicity at highest tested doses with reduction of cell survival below 40% and IC50 value of 40×103 nematocysts/mL. Both plant extracts significantly improved the survival of cells, so that the IC50 resulted 74×103 and 100×103 nematocysts/mL in the presence of A. comosus and C. papaya extracts, respectively, both used at 10 and 100 μg/mL. Taking into account that heterotrichous microbasic eurytele nematocysts are present mainly in tentacles, which Pelagia noctiluca utilizes both for predation and defence, this result is particularly interesting from both ecological and sanitary point of view and demonstrates the potential of these plants extracts against cnidarian venoms.

Modulatory Activities of Plant Extracts on Jellyfish Cytotoxicity

INTRODUCTION

The potential efficacy of selected plant extracts to counteract the dermal toxicity of jellyfish envenomation was investigated using an in vitro cell culture model.

METHODS

We studied plant extracts from Carica papaya, Ananas comosus, and Bouvardia ternifolia, known for their antivenom properties, in pairwise combinations with tissue homogenates of the jellyfish Pelagia noctiluca, Phyllorhiza punctata, and Cassiopea andromeda, to evaluate modulations of jellyfish cytotoxic effects. L929 mouse fibroblasts were incubated with pairwise jellyfish/plant extract combinations and examined by MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide).

RESULTS

C papaya and A comosus significantly lowered the cytotoxicity of P noctiluca and P punctata but induced a slight worsening of C andromeda cytotoxicity. Conversely, B ternifolia was protective against P punctata, ineffective against P noctiluca, and worsened C andromeda cytotoxicity.

CONCLUSIONS

Data showed species-specific and contrasting effects of plant extracts, suggesting that those containing protease activities, namely A comosus and C papaya, are more effective in lowering the cytotoxicity of jellyfish venom containing toxic peptidic factors such as phospholipase A. However, all examined plants require further investigation in vivo to evaluate their ability to counteract jellyfish injury to the skin.

Natural Compounds and Drug Discovery: Can Cnidarian Venom Play a Role?

Natural compounds extracted from organisms and microorganisms are an important resource for the development of drugs and bioactive molecules. Many such compounds have made valuable contributions in diverse fields such as human health, pharmaceutics and industrial applications. Presently, however, research on investigating natural compounds from marine organisms is scarce. This is somewhat surprising considering that the marine environment makes a major contribution to Earth's ecosystems and consequently possesses a vast storehouse of diverse marine species. Interestingly, of the marine bioactive natural compounds identified to date, many are venoms, coming from Cnidarians (jellyfish, sea anemones, corals). Cnidarians are therefore particularly interesting marine species, producing important biological compounds that warrant further investigation for their development as possible therapeutic agents. From an experimental aspect, this review aims to emphasize and update the current scientific knowledge reported on selected biological activity (antiinflammatory, antimicrobial, antitumoral, anticoagulant, along with several less studied effects) of Cnidarian venoms/extracts, highlighting potential aspects for ongoing research towards their utilization in human therapeutic approaches.

Stress-Induced Mucus Secretion and Its Composition by a Combination of Proteomics and Metabolomics of the Jellyfish Aurelia coerulea

BACKGROUND

Jellyfish respond quickly to external stress that stimulates mucus secretion as a defense. Neither the composition of secreted mucus nor the process of secretion are well understood.

METHODS

Aurelia coerulea jellyfish were stimulated by removing them from environmental seawater. Secreted mucus and tissue samples were then collected within 60 min, and analyzed by a combination of proteomics and metabolomics using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS), respectively.

RESULTS

Two phases of sample collection displayed a quick decrease in volume, followed by a gradual increase. A total of 2421 and 1208 proteins were identified in tissue homogenate and secreted mucus, respectively. Gene Ontology (GO) analysis showed that the mucus-enriched proteins are mainly located in extracellular or membrane-associated regions, while the tissue-enriched proteins are distributed throughout intracellular compartments. Tryptamine, among 16 different metabolites, increased with the largest-fold change value of 7.8 in mucus, which is consistent with its involvement in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway 'tryptophan metabolism'. We identified 11 metalloproteinases, four serpins, three superoxide dismutases and three complements, and their presence was speculated to be related to self-protective defense.

CONCLUSIONS

Our results provide a composition profile of proteins and metabolites in stress-induced mucus and tissue homogenate of A. coerulea. This provides insight for the ongoing endeavors to discover novel bioactive compounds. The large increase of tryptamine in mucus may indicate a strong stress response when jellyfish were taken out of seawater and the active self-protective components such as enzymes, serpins and complements potentially play a key role in innate immunity of jellyfish.

Antimicrobials from Cnidarians. A New Perspective for Anti-Infective Therapy?

The ability of microbes to counter the scientific and therapeutic advancements achieved during the second half of the twentieth century to provide effective disease treatments is currently a significant challenge for researchers in biology and medicine. The discovery of antibiotics, and the subsequent development of synthetic antimicrobial compounds, altered our therapeutic approach towards infectious diseases, and improved the quality and length of life for humans and other organisms. The current alarming rise in cases of antibiotic-resistance has forced biomedical researchers to explore new ways to recognize and/or produce new antimicrobials or to find other approaches for existing therapeutics. Aquatic organisms are known to be a source of compounds having the potential to play a role in fighting the battle against pathogenic microbes. In this connection, cnidarians occupy a pre-eminent role. Over the past few decades several studies have explored the antimicrobial/antibiotic properties of cnidarian extracts with the aim of isolating compounds possessing useful therapeutic features. This paper aims to review the existing data on this subject, taking into account the possible utilization of identified compounds.

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 <em>Pelagia noctiluca</em> 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 <em>Pelagia noctiluca</em>. 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 <em>in situ</em> and isolated nematocyst was found to be Ca²⁺ dependent. Furthermore, <em>Pelagia noctiluca</em> nematocysts were seen to retain their discharging capacity in distilled water. The toxicological evaluations were carried out mainly using the crude venom from <em>Pelagia noctiluca</em> 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 <em>Pelagia noctiluca</em> 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.

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.

Ecotoxicological assessment of the micelle encapsulator F-500

Surfactants are synthetic chemicals utilized as detergents and cleaning products or as dispersants and emulsifiers to face water pollution. In spite of this, due to their wide diffusion, surfactants can induce water and soil pollution, notably in developed countries, and can be toxic to organisms. Taking into account that the assessment of new compounds is mandatory in the European Union, in this research the ecotoxicity of fire-fighting micelle encapsulator F-500, newly utilized as dispersant in seawaters polluted with oil dumping, was evaluated. The assessment was carried out on a battery of test-organisms (freshwater algae, crustaceans, and larval fish; seawater algae, crustaceans, and bivalves; soil earthworms, and seeds) as well as on cultured cells (L-929 mouse fibroblasts), which were exposed to F-500 concentrations. According to the toxicity thresholds provided by GESAMP, F-500 resulted to be slightly or moderately toxic to all test-organisms, excluding the freshwater alga Pseudokirchneriella subcapitata that suffered highly toxic effects with IC50 values ranging from 0.21 to 0.49mg/L. The IC50 for mouse fibroblasts was 5.41µg/L after 24h treatment.

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 <em>Tigriopus fulvus</em>, 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 <em>Scyphidia</em> sp. on <em>Tigriopus fulvus</em> has been described and the occurrence of algae <em>Cocconeis</em> 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 <em>Tigriopus fulvus</em> is considered.

The role of Cnidaria in drug discovery. A review on CNS implications and new perspectives

Many organisms produce bioactive substances used in the production of drugs. In this context, Cnidaria occupy a major position; for this reason, research on new bioactive substances has focused upon them as an interesting target. As a matter of fact, substances and extracts able to fight human diseases have been found in cnidarians, several of which have been studied in laboratories using animal models or cell cultures and, at present, some are in the pre-clinical phase. This review aims to highlight the research on existing drugs or new drug candidates extracted from Cnidaria and the recent patents published in this field; furthermore, as many cnidarian venoms are known to have an impact on the CNS and on neuromuscular transmission, this review particularly considers the research concerning CNS drug discovery and pending patents.

Hemolytic venoms from marine cnidarian jellyfish - an overview

Cnidarian jellyfish are viewed as an emergent problem in several coastal zones throughout the world. Recurrent outbreaks pose a serious threat to tourists and bathers, as well as to sea-workers, involving health and economical aspects. As a rule, cnidarian stinging as a consequence of nematocyst firing induces merely local symptoms but cardiovascular or neurological complications can also occur. Hemolysis is a frequent effect of cnidarian stinging; this dangerous condition is known to be caused by several venoms and can sometimes be lethal. At present, the bulk of data concerning hemolytic cnidarian venoms comes from the study of benthic species, such as sea anemones and soft corals, but hemolytic factors were found in venoms of several siphonophore, cubozoan and scyphozoan jellyfish, which are mainly involved in the envenomation of bathers and sea-workers. Therefore, the aim of this paper is to review the scientific literature concerning the hemolytic venoms from cnidarian jellyfish taking into consideration their importance in human pathology as well as health implications and possible therapeutic measures.

Cytotoxic and cytolytic cnidarian venoms. A review on health implications and possible therapeutic applications

The toxicity of Cnidaria is a subject of concern for its influence on human activities and public health. During the last decades, the mechanisms of cell injury caused by cnidarian venoms have been studied utilizing extracts from several Cnidaria that have been tested in order to evaluate some fundamental parameters, such as the activity on cell survival, functioning and metabolism, and to improve the knowledge about the mechanisms of action of these compounds. In agreement with the modern tendency aimed to avoid the utilization of living animals in the experiments and to substitute them with in vitro systems, established cell lines or primary cultures have been employed to test cnidarian extracts or derivatives. Several cnidarian venoms have been found to have cytotoxic properties and have been also shown to cause hemolytic effects. Some studied substances have been shown to affect tumour cells and microorganisms, so making cnidarian extracts particularly interesting for their possible therapeutic employment. The review aims to emphasize the up-to-date knowledge about this subject taking in consideration the importance of such venoms in human pathology, the health implications and the possible therapeutic application of these natural compounds.

Effect of extracts from Spirulina platensis bioaccumulating cadmium and zinc on L929 cells

The uptake of cadmium and zinc by Spirulina platensis was investigated using a laboratory culture of this cyanobacterium. The cells were treated with metal concentrations increasing from 0.5 to 2.0 mg L(-1), in order to evaluate their adsorption capacity and survival potential. Afterwards, the cytotoxicity of cell extracts bioaccumulating heavy metals was evaluated on cultured L929 mouse fibroblasts. Cadmium was removed with higher yield (84.0-88.7%) than zinc (54.5-68.0%) and the maximum specific removal of these metals was 1.82 and 2.60 mg g(-1), respectively. Cadmium bioaccumulating algal extracts caused higher cell mortality of L929 cells than zinc accumulating ones, with a clear dose-response trend. EC(50) estimated by Trimmed Spearman-Karber (TSK) method were 7.21 and 9.59cells mL(-1) for cadmium and zinc, respectively. The capability to accumulate heavy metals could have a remarkable importance for the utilization of algal species in human or animal feeding.

Detection of free-living and plankton-bound vibrios in coastal waters of the Adriatic Sea (Italy) and study of their pathogenicity-associated properties

Culturable vibrios were isolated from water and plankton fractions collected during an 18-month sampling study performed along the north-central coast of the Adriatic Sea (Italy). Unculturable Vibrio vulnificus and V. parahaemolyticus were detected in plankton fractions by polymerase chain reaction amplification of DNA sequences for cytotoxin-haemolysin and thermolabile haemolysin respectively. The presence of V. parahaemolyticus, V. vulnificus and V. cholerae virulence genes and the expression of pathogenicity-associated traits were analysed in all isolates. The results showed the spreading of these properties among the environmental isolates and confirm the need of both monitoring the presence of vibrios in coastal areas and studying their pathogenicity potential in order to properly protect human health.

Cytotoxicity in vitro analysis of ceramic materials for ''metal free'' prosthetic substructures

AIM

The aim of this study was to investigate the in vitro cytotoxicity of 5 ceramic materials for metal-free fixed prosthodontics: In-Ceram, Cergo, IPS Empress II, Cercon ZrO2, Finesse All Ceram compared each other and to commercially pure Titanium (CpTi).

METHODS

The materials, prepared directly from manufacturers as 10 mm diameter and 3 mm thickness disks, have been tested following the ISO 10993-l guidelines, performing the in vitro cytotoxicity test with the use of mouse's cells, fibroblasts L-929, isolated by muscular tissue and cultured in an appropriate medium. The MTT test has been used to evaluate the cell viability through the succinate dehydrogenase enzyme activity. The originality of this investigation is that all the materials examined have been tested under the same conditions: the cytotoxicity test has been performed on these materials at the same time, in the same period, under the same conditions of temperature and humidity and by the same operator.

RESULTS

Not all tested materials were free from cytotoxicity. Cercon, within the limits of this in vitro study, showed the lower cytotoxicity.

CONCLUSIONS

This in vitro study suggested that ceramic materials for metal free prosthetic substructures are in competition with the CpTi which is very used in implant prosthodontics.

Mesozooplankton assemblage and first record of Paracartia grani Sars G.O., 1904 (Copepoda: Calanoida) in the Western harbour of Genova (Ligurian Sea)

Harbours are characterized by high pollutant charge and by the occurrence of well adapted and resistant species. This paper reports the results of an annual plankton survey (May 1997-June 1998) carried out in the western harbour of Genova (Ligurian Sea) and in its mouth. Plankton samples were collected by horizontal trawls using a WP2 net. Copepods were the bulk of plankton in almost all samples. Eight copepod species were recognized: Paracalanus parvus and Acartia clausi were the most abundant. The first record of Paracartia grani in the harbour of Genova is here reported; this species, which is known to occur in polluted harbour waters of the Mediterranean Sea and was found in semi-confined Mediterranean and Atlantic coastal areas, was dominant during October 1997. Also Clausocalanus spp., Centropages typicus, Oithona helgolandica, Oithona nana, Farranula spp., Eurytemora spp., Isias clavipes and Lucicutia spp. were frequently sampled. Among other zooplankters, cladocerans, ostracods and tunicates occurred frequently, while cnidarians, mysids and chaetognaths showed low densities. These results show the occurrence of a well defined harbour plankton and point out the differences between harbour and neritic plankton of the Gulf of Genova.

Video-based eye tracking: our experience with Advanced Stimuli Design for Eye Tracking software

We present an independent, flexible, and easily programmable software program for generating a wide set of visual stimuli paradigms in eye-movement studies. The software, called ASTIDET (Advanced Stimuli Design for Eye Tracking), has been interfaced in real time with a high speed video-based eye tracking system in order to obtain a reliable measurement of saccades. Two saccadic paradigms have been tested (gap and memory guided tasks) in 10 normal subjects. The preliminary results confirm that ASTIDET is a user-friendly software and can be interfaced with a video-based eye-tracking device in order to obtain reliable measurement of saccades.

A fast centrifuge method for nematocyst isolation from Pelagia noctiluca Forskal (Cnidaria: Scyphozoa)

Nematocyst isolation from surrounding tissue is an important step to characterize Cnidarian venom. Although several protocols have been used to extract venoms from cnidarian tissues, the complete isolation of nematocysts from tissue is still difficult. The goal of the present work was to evaluate the effectiveness of three different media, Percoll, Ficoll and Methylcellulose in isolating nematocysts from Pelagia noctiluca tentacles by centrifugation. The complete sedimentation of nematocysts and tissue fragments to the bottom of the test tubes was observed in Ficoll and Methylcellulose suspensions. The best result was obtained using a discontinuous density gradient of Percoll: three types of nematocysts were concentrated in three different fractions along the density gradient. Protein assay and preliminary chromatographic analyses confirmed these results.

Animal age-, dose- and cell line-dependent growth of human neuroblastoma in nude mice. A statistical analysis

Cells lines from human neuroblastoma (NB) and T/lymphoma (T-L) were injected subcutaneously (sc) in female CD1 nu/nu athymic nude mice. Results obtained after the observation of tumour growth were statistically analyzed by SAS. The following four parameters were considered: 1) dose of injected cells, 2) type of injected tumour (NB or T-L), 3) age of mice after individuation of three groups of animals (group A, 4-9 weeks old, group B, 9-20 weeks old, group C, > 20 weeks old), 4) injected cell line within the same tumour type. Latency time (LT), corresponding to the interval between cell inoculum and the appearance of a 5 mm diameter subcutaneous mass, and survival time (ST), corresponding to the interval between cell inoculum and the appearance of a 20 mm diameter subcutaneous tumour mass, were considered to evaluate tumour growth. Results showed that mass progression is affected by the number of injected cells and both LT and ST are age- and dose-dependent; furthermore, significant differences were recorded by using different NB and T-L cell lines. Group C showed longer LT than other groups; group B animals showed a statistically significant longer ST than groups A and C (p < 0.001). Our results indicate that growth of human NB in athymic mice is faster in young animals, which also show a significantly poorer prognosis, while better ST was observed in old and middle-aged animals. Results show statistically significant differences of both LT and ST in animals differing in age and in animals inoculated with different cell amounts. These results seem not to be related with biological properties of NB cells too, since neither the occurrence of MYCN amplification nor chromosome 1p deletion significantly modified such behaviour.

Ecology of planktonic heterotrophic flagellates. A review

In aquatic environments heterotrophic flagellates are an important component within the microbial loop and the food web, owing to their involvement in the energy transfer and flux and as an intermediate link between bacteria and primary producers, and greater organisms, such as other protists and metazoan consumers. In the microbial loop heterotrophic flagellates highly contribute to fast biomass and nutrient recycling and to the production in aquatic environments. In fact, these protists consume efficiently viruses, bacteria, cyanobacteria and picophytoplankton, and are grazed mainly by other protists, rotifers and small crustaceans. In this paper the knowledge about these unicellular organisms is reviewed, taking into particular account their ecological relationships and trophic role within the plankton community of marine and freshwater environments.

Cytotoxicity of the venom of Pelagia noctiluca forskål (Cnidaria: Scyphozoa)

The activity of Pelagia noctiluca venom was never assessed on cultured cells; therefore, we have evaluated on V79 cells the cytotoxicity, genotoxicity and ATP depletion induced after treatment. Venom did not cause alteration on cell DNA, but showed remarkable cytotoxic properties. With the highest nematocyst concentration (150,000 nematocyst/ml) 74 and 39% cells survived after 1 and 3 h, respectively, when evaluated by Trypan blue. Treated cells showed increased ATP levels during the same time. Preliminary HPLC analyses have showed the occurrence of a protein containing peak.

Variations of ATP content in V79 cells treated with crude toxins of--Aequorea aequorea (Cnidaria: Hydrozoa) and Rhizostoma pulmo (Cnidaria: Scyphozoa). A preliminary study

The toxicity of Cnidaria exerts a noticeable influence on some human activities, such as fishery and bathing, and on public health. As toxins of Mediterranean Cnidaria are located in nematocysts and in tissues, in this study the influence of crude toxins (nematocyst and surrounding tissue venom) extracted from the jellyfish Aequorea aequorea and Rhizostoma pulmo on ATP content of cultured V79 cells was assessed. Using the crude toxin of A. aequorea an increase of ATP levels in treated cells was noted; highest values (41.2 10(-7) mM/ml after 180 min treatment) were reached using the highest dose. Otherwise, a generalized decrease of ATP levels was observed treating cells with crude toxin of R. pulmo; recorded values showed the complete depletion of cell ATP at 115 min treatment with the highest dose. A statistical significance was recorded between treatment times and between doses using crude toxin of R. pulmo, and only between treatment times for A. aequorea.

An ultrastructural study of the Antarctic calanoid Copepod Metridia gerlachei giesbrecht, 1902. Adult female

Scanning electron microscopy (SEM) techniques can highly contribute to the knowledge of body structures in order to differentiate between different species or between varieties within the same species. This is particularly important in extreme environments, such as in Antarctic waters, where the evolution efforts have promoted the development of endemisms. In this work the external anatomy of Metridia gerlachei (Copepoda, Calanida) adult females, sampled during the Italian Oceanographic Campaign in Antarctica 1987-88, was described by SEM, particularly considering some swimming legs and the genital abdominal joint. The descriptions already reported have been verified and some morphological details have been better emphasized. As concerns the P2, the hook process of the first segment of endopod and a series of spines vaguely indicated, but not defined, in previous descriptions have been clearly evidenced. In the P5 the occurrence of three well separated free segments and the location of a marginal sets have been shown. The ultrastracture of the genital segment showed that a clear areola surrounds the genital field.

Application of the principal component analysis (PCA) to the ecological study of an artificial environment: the tunny-fishing net of Camogli (Ligurian Sea)

The management of the marine environment and resource exploitation depend on the knowledge of both water conditions and ecological relationships between organisms. In the framework of fishing problems, an adequate food availability is important in order to allow maintaining and growth of fish stocks. The tunny-fishing of Camogli, owing to the coco-fibre texture of its net, can improve the trophic resources allowing the settlement of organisms eaten by fish. The distribution and composition of settled organisms was studied during the campaign 1988 by microscopical methods. The results have been elaborated by using multivariate (PCA) methods. Foraminifers, ciliates, hydroids, nematodes and copepods were the mainly observed groups. Their variations with season and depth and the relationships with caught fish species are presented. The elaboration of data by PCA allowed an easy and complete interpretation of the obtained complex data set showing the existence of a "rope" and of a "depth" effect.

Toxicity of Actinia equina (Cnidaria: Anthozoa) crude venom on cultured cells

The toxicity of Cnidaria is a subject of high concern owing to its influence on human activities and public health and to the implications in ecological relationships between organisms. In order to simulate as much as possible the natural conditions and the consequences of stinging against injured cells, as well considering that Cnidarian venoms are located not only in nematocysts but also in tissues, the cytotoxicity and genotoxicity of crude extracts from nematocyst and surrounding tissues of the sea-anemone Actinia equina (Cnidaria: Anthozoa) were assessed on cultured fibroblasts (V79). The cytotoxicity was remarkable and cell survival was highly reduced at highest tested concentration (150,000 nematocysts/ml); using the Trypan blue dye exclusion test, only 40% of treated cells survived after the first hour of treatment and viable cells were not counted after the second hour. Also the results obtained utilizing the Neutral Red assay showed serious effects of crude toxin (only 31.5% and 12.6% cell survival after one and three hours respectively). Genotoxic effects were not observed at tested doses.

In vitro evaluation of the cytotoxic, hemolytic and clastogenic activities of Rhizostoma pulmo toxin(s)

Cytotoxic, hemolytic and clastogenic activities of Rhizostoma pulmo toxin(s) contained in the jelly tissue free of nematocysts were investigated in mammalian cells with in vitro procedures. At the concentration of 37.6 microg/ml the tissue protein produced the death of 50% V79 cells; a similar potency was observed in terms of hemolytic activity. The toxin(s) was not clastogenic for human lymphocytes in culture at the concentration of 5 microg/ml.

Toxicity of jellyfish and sea-anemone venoms on cultured V79 cells

Cnidarian toxins exert an influence on human activities and public health. The cytotoxicity of crude toxins (nematocyst and surrounding tissue venom) of Aequorea aequorea, Rhizostoma pulmo and Anemonia sulcata was assessed on V79 cells. Rhizostoma pulmo and Anemonia sulcata crude venoms showed remarkable cytotoxicity and killed all treated cells at highest tested concentration within 2 and 3 hr, respectively. Aequorea aequorea crude venom greatly affected growth rate during long-term experiments. No genotoxic effect was observed.

Mitochondrial alteration caused by cnidarian toxins: a preliminary study

Cnidarians contain different toxins causing cytotoxic and cytolytic effects probably due to cell membrane alterations. Mitochondria were used here as an experimental model system to characterize the action of cnidarian toxins. Toxin from the sea anemone Anemonia sulcata affects the function of rat liver mitochondria. Effects are dose- and time-dependent and they disappear when Ca2+ is absent. This toxin could therefore have a phospholipase-like action, as reported for other cnidarians. Mitochondrial alterations by cnidarian toxins could therefore be a particular case of a general mechanism of toxicity directed towards biological membranes.

HPLC separation of toxic fraction components extracted from planktonic and benthic Cnidaria

HPLC separation of crude extract components derived from nematocysts and extranematocystic tissues of macroplanktonic jellyfish Aequorea aequorea and Rhizostoma pulmo and benthic sea-anemones Actinia equina and Anemonia sulcata was carried out by different columns. A satisfactory peak separation was obtained analyzing the toxin of Rhizostoma pulmo by cationic and C18 columns. Low molecular weight fragments were separated by C18 column and U.V. monitored varying pH values and obtaining the displacement of significant peaks. Clear differences between chromatographic plots concerning planktonic and benthic species was evidenced by anionic column; this result can point out a clear ecological analogy between species living in the same environment and a similar toxin biosynthesis, due to selective actions related to both the environment and the phylogenetic relationships; these organisms could have developed similar mechanisms useful to tackle the environment.

Gamma-interferon and retinoic acid synergize in inhibiting the growth of human neuroblastoma cells in nude mice

We have investigated the effects of retinoic acid (RA), human recombinant gamma interferon (gamma-IFN), and the association of both agents on the growth of human neuroblastoma (NB) cells in [CD1(nu/nu)] nude mice. Two human NB cell lines, namely LAN-5 and GI-LI-N, were previously adapted to grow in syngeneic animals for 7 consecutive passages. At the eighth passage, only animals which developed 10-mm diameter tumors within 40 days from xenograft were admitted to the study. RA and/or gamma-IFN were administered subcutaneously 3-5 days per week for 3 consecutive weeks. The number of days necessary for each tumor mass to grow up to 20 mm diameter (in vivo doubling time, ivDT) was then evaluated. Tumor growth was significantly inhibited in gamma-IFN (P less than 0.005) and RA (P less than 0.05) treated mice grafted with GI-LI-N. The combination of the two agents did not further enhance ivDT. The tumor growth inhibition was not statistically significant in LAN-5 bearing mice treated with RA or gamma-IFN alone, while a synergistic effect between the two drugs was observed (P less than 0.05). We conclude that parenteral combined administration of RA and gamma-IFN may prove to be useful in inhibiting the growth of tumors derived from human NB cells resistant to single inducers.

A new human highly tumorigenic neuroblastoma cell line with undetectable expression of N-myc

A peculiar human cell line (GI-ME-N) derived from the metastatic bone marrow of a 2-yr-old patient with stage IV neuroblastoma (NB) was extensively characterized. Cell-type-specific markers, tumorigenicity in nude mice, morphology, cytogenetics, and amplification/expression of the N-myc gene were evaluated. All metaphases presented the typical 1p deletion. Surface markers specific for NB cells, vimentin, and neurofilament proteins were all clearly detectable with immunofluorescence and/or western blot procedures. Moreover, it was found that GI-ME-N cells did not express N-myc oncogene or HLA class 1 antigens, and were not classified as peripheral neuroectodermal tumor cells. However, extremely short latency and survival times, comparable to peripheral neuroectodermal tumor cells, were observed in nude mice grafted with GI-ME-N. In addition, no correlations were observed in tumorigenicity of N-myc amplified (IMR32) versus unamplified (SK-N-SH GI-ME-N) human NB cell lines in nude mice. We conclude that N-myc amplification/expression do not correlate with the aggressiveness of human NB in athymic animals, which is not always explained by the peripheral neuroectodermal tumor cell nature of the malignant cells, either.

[Biometrico-statistical evaluation of a biological sample]

The total animal population percentage composition, found during period May-August 1979 on tunny-fishing coco-fibres nets in Camogli (Genoa), has been valued in relation to the depth. In particular, connections between population and presence of some fish species draughted has been studied, considering ecological, reproductive and trophic habits of fishes, in order to value relations between the influence these populations exert on fishing and biological characteristics of the quantitatively more meaningful fish species.