The toxic dinoflagellate Alexandrium catenella adversely affects early life stages of tehuelche scallop.

The effects of the toxic dinoflagellate Alexandrium catenella were investigated on growth, survival, and histopathology in larvae and spat of the Tehuelche scallop Aequipecten tehuelchus from Patagonia, Argentina. The study consisted of laboratory incubations of scallop larvae/spat with A. catenella, using environmentally realistic abundances of the dinoflagellate. Survival, growth, and histopathological effects were documented for scallop larvae/spat before, during, and after 7-day-long exposure to A. catenella. The scallops were grouped in flasks containing 0 (control), 20, 200, and 2000 cells mL-1 of A. catenella. The presence of A. catenella induced reduced larvae survival after 24 h, whereas a clear effect was observed after 3 days (survival of control larvae 95%, 72, and 79% for 20 and 200 cells mL-1, respectively, and 43% for 2000 cells mL-1). The growth rates of the control larvae and those exposed to 20 mL-1 cells were significantly different from zero. Histopathological effects (melanization, loss of connective tissue, necrosis, and inflammatory responses) were observed in spat exposed to A. catenella. These effects were more pronounced at the highest dinoflagellate concentration. Blooms of A. catenella frequently coincide with the reproductive season of A. tehuelchus, thus there is a need to further study the relationship between harmful algal blooms and the effect on scallops' natural populations in the region.

Persistent COVID-19 symptoms 1 year after hospital discharge: A prospective multicenter study.

OBJECTIVE: To determine the health status and exercise capacity of COVID-19 survivors one year after hospital discharge. METHODS: This multicenter prospective study included COVID-19 survivors 12 months after hospital discharge. Participants were randomly selected from a large cohort of COVID-19 patients who had been hospitalized until 15th April 2020. They were interviewed about persistent symptoms, underwent a physical examination, chest X-ray, and a 6-minute walk test (6MWT). A multivariate analysis was performed to determine the risk factors for persistent dyspnea. RESULTS: Of the 150 patients included, 58% were male and the median age was 63 (IQR 54-72) years. About 82% reported ≥1 symptoms and 45% had not recovered their physical health. The multivariate regression analysis revealed that the female sex, chronic obstructive pulmonary disease, and smoking were independent risk factors for persistent dyspnea. Approximately 50% completed less than 80% of the theoretical distance on the 6MWT. Only 14% had an abnormal X-ray, showing mainly interstitial infiltrates. A third of them had been followed up in outpatient clinics and 6% had undergone physical rehabilitation. CONCLUSION: Despite the high rate of survivors of the first wave of the COVID-19 pandemic with persistent symptomatology at 12 months, the follow-up and rehabilitation of these patients has been really poor. Studies focusing on the role of smoking in the persistence of COVID-19 symptoms are lacking.

A phylogenetically unresolved apicomplexan (APXSc) causing swirl lesions in the Tehuelche scallop, Aequipecten tehuelchus, from the Southwest Atlantic coast.

The study reports a previously unknown apicomplexan (APXSc) parasite infecting wild scallops Aequipecten tehuelchus (d'Orbigny, 1842) from two separate areas (La Tapera and Punta Conos) of the San José gulf, in Patagonia Argentina. Histology, transmission electron microscope, molecular analyses and in situ hybridization were performed to describe the morphology of APXSc, and confirm its phylogenetic status. The prevalence of APXSc infection was 24% and 72% in scallops from La Tapera and Punta Conos, respectively. Seasonal variation was observed for scallops from La Tapera, recording highest prevalence in summer. A positive relationship between the presence of the APXSc and the size of the scallops was observed. A SSU rDNA consensus sequence of 1758 base pairs was generated which has a 94.8% identity to sequences obtained from a pathogenic apicomplexan parasite infecting Ostrea chilensis in New Zealand, but not closely related to other apicomplexans. The asexual reproduction, i.e. merogony, occurs in the Tehuelche scallop whilst the gamogonic and sporogonic stages were absent, suggesting a yet unknown definitive host. Severe host inflammation response involving fibroblast-like hemocytes surrounding the APXSc in the form of granuloma-like "swirls" is characteristic for this apicomplexan infection. Further studies are needed to reveal the life cycle, and presumable pathogenicity of APXSc.

A single clonal lineage of transmissible cancer identified in two marine mussel species in South America and Europe.

Transmissible cancers, in which cancer cells themselves act as an infectious agent, have been identified in Tasmanian devils, dogs, and four bivalves. We investigated a disseminated neoplasia affecting geographically distant populations of two species of mussels (Mytilus chilensis in South America and M. edulis in Europe). Sequencing alleles from four loci (two nuclear and two mitochondrial) provided evidence of transmissible cancer in both species. Phylogenetic analysis of cancer-associated alleles and analysis of diagnostic SNPs showed that cancers in both species likely arose in a third species of mussel (M. trossulus), but these cancer cells are independent from the previously identified transmissible cancer in M. trossulus from Canada. Unexpectedly, cancers from M. chilensis and M. edulis are nearly identical, showing that the same cancer lineage affects both. Thus, a single transmissible cancer lineage has crossed into two new host species and has been transferred across the Atlantic and Pacific Oceans and between the Northern and Southern hemispheres.

[Sequential treatment with Mitomycin C and BCG in non muscle invasive bladder cancer.] / Tratamiento secuencial con Mitomicina C y BCG en el cáncer vesical no músculo-invasivo.

Bacilus Calmette-Guerin (BCG) administered intravesical is an effective therapy in non muscle invasive bladder cancer (NMIBC), but it presents limitations regarding recurrence and toxicity. For years, many case series have been published where sequential therapy with BCG and Mitomycin C (MMC) was tried. In this article, we perform a review of the data supplied by these articles with the aim to determine the safety and efficacy of combination, and what is the group of patients it should be indicated. Many studies show that combination therapy did not cause more toxicity and improved the interval free of disease with decrease of tumor progression compared to BCG or MMC monotherapy. Therefore, a combination of MMC and BCG therapy seems safe, but more clinical studies are required for a future evaluation.

cis-Platinum Complex Encapsulated in Self-Assembling Cyclic Peptide Dimers.

A new cyclic peptide dimer that encapsulates cisplatin complexes in its internal cavity is described. The resulting complex showed cytotoxic activity at A2780 ovarian cancer cell lines independent of acquired platinum resistance.

Bioinspired Artificial Sodium and Potassium Ion Channels.

In Nature, all biological systems present a high level of compartmentalization in order to carry out a wide variety of functions in a very specific way. Hence, they need ways to be connected with the environment for communication, homeostasis equilibrium, nutrition, waste elimination, etc. The biological membranes carry out these functions; they consist of physical insulating barriers constituted mainly by phospholipids. These amphipathic molecules spontaneously aggregate in water to form bilayers in which the polar groups are exposed to the aqueous media while the non-polar chains self-organize by aggregating to each other to stay away from the aqueous media. The insulating properties of membranes are due to the formation of a hydrophobic bilayer covered at both sides by the hydrophilic phosphate groups. Thus, lipophilic molecules can permeate the membrane freely, while the small charged or very hydrophilic molecules require the assistance of other membrane components in order to overcome the energetic cost implied in crossing the non-polar region of the bilayer. Most of the large polar species (such as oligosaccharides, polypeptides or nucleic acids) cross into and out of the cell via endocytosis and exocytosis, respectively. Nature has created a series of systems (carriers and pores) in order to control the balance of small hydrophilic molecules and ions. The most important structures to achieve these goals are the ionophoric proteins that include the channel proteins, such as the sodium and potassium channels, and ionic transporters, including the sodium/potassium pumps or calcium/sodium exchangers among others. Inspired by these, scientists have created non-natural synthetic transporting structures to mimic the natural systems. The progress in the last years has been remarkable regarding the efficient transport of Na(+) and K(+) ions, despite the fact that the selectivity and the ON/OFF state of the non-natural systems remain a present and future challenge.