The usefulness of intraoperative sodium fluorescein in the surgical treatment of relapsed high-grade brain tumors in pediatric patients.

PURPOSE: We report the usefulness of intraoperative sodium fluorescein (SF) in the surgical treatment of relapsed high-grade brain tumors in pediatric neurosurgery. METHODS: We describe our protocol for intraoperative SF and three cases of patients between 5 and 11 years diagnosed and surgically treated for relapsed high-grade brain tumors using SF. RESULTS: The 560-nm microscope filter enables the use of low doses of this fluorochrome. A dose of 3 mg/kg of patient weight of 10% SF, administered intravenously, is safe and effective in children. The effect of SF was immediate, providing a clear margin between the tumor and healthy tissue, which enabled good tumor resection. We observed no adverse effects in the postoperative period, and the patients evolved satisfactorily. CONCLUSIONS: To the best of our knowledge, we describe for the first time the use of fluorescein in reoperations of relapsed high-grade brain tumors in childhood with promising results. Using SF in children is a safe, affordable, and effective technique that offers an excellent intraoperative image, being a feasible option to improve oncological resection. This study is one of the few that uses SF in pediatric neurosurgery, where it could be very beneficial.

Identification of Biomolecules Involved in the Adaptation to the Environment of Cold-Loving Microorganisms and Metabolic Pathways for Their Production.

Cold-loving microorganisms of all three domains of life have unique and special abilities that allow them to live in harsh environments. They have acquired structural and molecular mechanisms of adaptation to the cold that include the production of anti-freeze proteins, carbohydrate-based extracellular polymeric substances and lipids which serve as cryo- and osmoprotectants by maintaining the fluidity of their membranes. They also produce a wide diversity of pigmented molecules to obtain energy, carry out photosynthesis, increase their resistance to stress and provide them with ultraviolet light protection. Recently developed analytical techniques have been applied as high-throughoutput technologies for function discovery and for reconstructing functional networks in psychrophiles. Among them, omics deserve special mention, such as genomics, transcriptomics, proteomics, glycomics, lipidomics and metabolomics. These techniques have allowed the identification of microorganisms and the study of their biogeochemical activities. They have also made it possible to infer their metabolic capacities and identify the biomolecules that are parts of their structures or that they secrete into the environment, which can be useful in various fields of biotechnology. This Review summarizes current knowledge on psychrophiles as sources of biomolecules and the metabolic pathways for their production. New strategies and next-generation approaches are needed to increase the chances of discovering new biomolecules.

Proteomic analysis of plasma proteins of high-flux haemodialysis and on-line haemodiafiltration patients reveals differences in transthyretin levels related with anaemia.

A large proportion of end-stage renal disease (ESRD) patients under long-term haemodialysis, have persistent anaemia and require high doses of recombinant human erythropoietin (rhEPO). However, the underlying mechanisms of renal anaemia have not been fully elucidated in these patients. In this study, we will be focusing on anaemia and plasma proteins in ESRD patients on high-flux haemodialysis (HF) and on-line haemodiafiltration (HDF), to investigate using two proteomic approaches if patients undergoing these treatments develop differences in their plasma protein composition and how this could be related to their anaemia. The demographic and biochemical data revealed that HDF patients had lower anaemia and much lower rhEPO requirements than HF patients. Regarding their plasma proteomes, HDF patients had increased levels of a protein highly similar to serotransferrin, trypsin-1 and immunoglobulin heavy constant chain alpha-1, and lower levels of alpha-1 antitrypsin, transthyretin, apolipoproteins E and C-III, and haptoglobin-related protein. Lower transthyretin levels in HDF patients were further confirmed by transthyretin-peptide quantification and western blot detection. Since ESRD patients have increased transthyretin, a protein that can aggregate and inhibit transferrin endocytosis and erythropoiesis, our finding that HDF patients have lower transthyretin and lower anaemia suggests that the decrease in transthyretin plasma levels would allow an increase in transferrin endocytosis, contributing to erythropoiesis. Thus, transthyretin could be a critical actor for anaemia in ESRD patients and a novel player for haemodialysis adequacy.