Characterization of a Strain of Fukuyoa paulensis (Dinophyceae) from the Western Mediterranean Sea

A single cell of the dinoflagellate genus Fukuyoa was isolated from the island of Formentera (Balearic Islands, west Mediterranean Sea), cultured, and characterized by morphological and molecular methods and toxin analyses. This is the first report of the Gambierdiscus lineage (genera Fukuyoa and Gambierdiscus) from the western Mediterranean Sea, which is cooler than its eastern basin. Molecular analyses revealed that the Mediterranean strain belongs to F. paulensis and that it bears LSU rDNA sequences identical to New Zealand, Australian, and Brazilian strains. It also shared an identical sequence of the more variable ITS‐rDNA with the Brazilian strain. Toxin analyses showed the presence of maitotoxin, 54‐deoxyCTX1B, and gambieric acid A. This is the first observation of the two latter compounds in a Fukuyoa strain. Therefore, both Gambierdiscus and Fukuyoa should be considered when as contributing to ciguatera fish poisoning. Different strains of Fukuyoa form a complex of morphologically cryptic lineages where F. paulensis stands as the most distantly related nominal species. The comparison of the ITS2 secondary structures revealed the absence of CBCs among strains. The study of the morphological and molecular traits depicted an unresolved taxonomic scenario impacted by the low strains sampling.     

Characterization of Prorocentrum elegans and Prorocentrum levis (Dinophyceae) from the southeastern Bay of Biscay by morphology and molecular phylogeny

Benthic Prorocentrum species can produce toxins that adversely affect animals and human health. They are known to co‐occur with other bloom‐forming, potentially toxic, benthic dinoflagellates of the genera Ostreopsis, Coolia, and Gambierdiscus. In this study, we report on the presence of P. elegans M.Faust and P. levis M.A.Faust, Kibler, Vandersea, P.A. Tester & Litaker from the southeastern Bay of Biscay. Sampling was carried out in the Summer‐Autumn 2010–2012 along the Atlantic coast of the Iberian Peninsula, but these two species were only found in the northeastern part of the Peninsula. Strains were isolated from macroalgae collected from rocky‐shore areas bordering accessible beaches. Morphological traits of isolated strains were analyzed by LM and SEM, whereas molecular analyses were performed using the LSU and internal transcribed spacer (ITS)1‐5.8S‐ITS2 regions of the rDNA. A bioassay with Artemia fransciscana and liquid chromatography–high‐resolution mass spectrometry analyses were used to check the toxicity of the species, whose results were negative. The strains mostly corresponded to their species original morphological characterization, which is supported by the phylogenetic analyses in the case of P. levis, whereas for P. elegans, this is the first known molecular characterization. This is also the second known report of P. elegans.     

Evolutionary Consequences of Mutation and Selection within an Individual

Whether in sexual or asexual organisms, selection among cell lineages during development is an effective way of eliminating deleterious mutations. Using a mathematical analysis, we find that relatively small differences in cell replication rates during development can translate into large differences in the proportion of mutant cells within the adult, especially when development involves a large number of cell divisions. Consequently, intraorganismal selection can substantially reduce the deleterious mutation rate observed among offspring as well as the mutation load within a population, because cells rather than individuals provide the selective ``deaths' necessary to stem the tide of deleterious mutations. The reduction in mutation rate among offspring is more pronounced in organisms with plastic development than in those with structured development. It is also more pronounced in asexual organisms that produce multicellular rather than unicellular offspring. By effecting the mutation rate, intraorganismal selection may have broad evolutionary implications; as an example, we consider its influence on the evolution of ploidy levels, finding that cell-lineage selection is more effective in haploids and tends to favor their evolution.     

Delivery of immunostimulatory monoclonal antibodies by encapsulated hybridoma cells

Immunostimulatory monoclonal antibodies are immunoglobulins directed toward surface proteins of immune system cells that augment the immune response against cancer in a novel therapeutic fashion. Exogenous administration of the recombinant humanized immunoglobulins is being tested in clinical trials with agents of this kind directed at a variety of immune-controlling molecular targets. In this study, the encapsulation of antibody-producing hybridoma cells was tested in comparison with the systemic administration of monoclonal antibodies. Hybridomas producing anti-CD137 and anti-OX40 mAb were encapsulated in alginate to generate microcapsules containing viable cells that secrete antibody. Immobilized cells in vitro were able to release the rat immunoglobulin produced by the hybridomas into the supernatant. Microcapsules were implanted by injection into the subcutaneous tissue of mice and thereby provided a platform for viable secreting cells, which lasted for more than 1 week. The pharmacokinetic profile of the rat monoclonal antibodies following microcapsule implantation was similar to that attained following an intraperitoneal administration of the purified antibodies. The rat–mouse hybridoma cells did not engraft as tumors in immunocompetent mice, while they lethally xenografted in immunodeficient mice, if not microencapsulated. The antitumor therapeutic activity of the strategy was studied on established CT26 colon carcinomas resulting in complete tumor eradication in an elevated fraction of cases and strong tumor-specific CTL responses with either anti-CD137 or anti-OX40 producing hybridomas, thus offering proof of the concept. This form of administration permitted combinations of more than one immunostimulatory monoclonal antibody to exploit the synergistic effects such as those known to be displayed by anti-CD137 and anti-OX40 mAb.     

History, challenges and perspectives of cell microencapsulation

Cell microencapsulation continues to hold significant promise for biotechnology and medicine. The controlled, and continuous, delivery of therapeutic products to the host by immunoisolated cells is a potentially cost-effective method to treat a wide range of diseases. Although there are several issues that need to be addressed, including capsule manufacture, properties and performance, in the past few years, a stepwise analysis on the essential obstacles and limitations has brought the whole technology closer to a realistic proposal for clinical application. This paper summarizes the current situation in the cell encapsulation field and discusses the main events that have occurred along the way.     

Impact factor of Revista Iberoamericana de Micología

The impact factor is a bibliometric indicator published annually in the Journal Citation Reports, and widely regarded as a quality ranking of the journals included in this database. The problem with this indicator is that the impact factor of several journals not listed in the Science Citation Index database is largely unknown. The aim of this study was to analyze the 2001 national and international impact factor of Revista Iberoamericana de Micología. The National impact factor of Revista Iberoamericana de Micología was obtained by adding the number of cites in 2001 from a total of 87 Spanish medical journals of greater scientific quality. Also, bibliographical references from Spanish journals indexed in the 2001 Journal Citation reports database have been included to determine the international impact factor of this analyzed journal. Revista Iberoamericana de Micología received a total of 62 cites from published articles in 1999 to 2001, coming from 20 different journals, being their self-citation index 10.1%. The journal with the highest number of cites to Revista Iberoamericana de Micología was Journal of Clinical Microbiology, with 12 cites (19.3%). According to this findings the national and international impact factor of Revista Iberoamericana de Micología was 0.266 and 0.606, respectively. The impact factor of Revista Iberoamericana de Micología, although not included in the Science Citation Index database, was higher than other Journal Citation Reports. Moreover, Revista Iberoamericana de Micología received most of its citations from high impact factor journals included in the Journal Citation Reports database. These data support the international recognition of the scientific level of the journal.     

Phytoplankton communities and biomass size structure (fractionated chlorophyll “a”), along trophic gradients of the Basque coast (northern Spain)

Eutrophication is a major threat to coastal ecosystems. Within Europe, the Water Framework Directive (WFD) has established the need of developing methods of assessment. Bulk chlorophyll “a” is used world-wide as an indicator of eutrophication. However, the size structure of the phytoplankton communities has not been investigated, in detail, in relation to eutrophication pressures. This study investigates the suitability of fractionated chlorophyll “a” (<10 and >10 μm), as an indicator of eutrophication. Along the Basque coast (northern Spain) several water bodies, ranging from offshore waters to the heads of the estuaries, were surveyed during 2008. Physico-chemical conditions and chlorophyll “a” showed a distinct spatial gradient. Trophic richness increased towards the middle and inner parts of the estuaries, where nutrient inputs, from natural or anthropogenic sources, together with the residence time of the water are usually higher. In summer, phytoplankton biomass and abundance decreased, generally, in offshore and coastal waters; in estuaries, they tended to increase. The chlorophyll distribution within the two size fractions was coherent with the phytoplankton taxonomic composition. In summer, the relative abundance of small-sized cells (diatoms and non-siliceous taxa) increased. The relationships between size-fractionated chlorophyll and physico-chemical variables differed, when comparing the offshore and coastal waters, with the estuaries. In the offshore and coastal waters, a strong seasonality was observed; in estuaries, an important spatial component was found. Fractionated chlorophyll provided complementary useful information on anthropogenic pressures. However, more research is necessary to utilise this variable as a tool for ecological status assessment, within the WFD.