New Productive Technologies, Ethics and Legislation in Brazil: A Delayed Debate

This paper focuses on the debate about the utilization of new reproductive technologies in Brazil, and the paths taken in the Brazilian National Congress in an attempt to draw up legislation to regulate the clinical practice of human assisted reproduction. British documents, such as the Warnock Report and Human Fertilization and Embriology Authority (HFEA) are used for thorough reference. The analysis of the Law Projects in the National Congress, the Resolution by the Federal Medicine Council, Resolution 196/96 and documents by the Ministério Público (Public Prosecution Office), suppled the bases for the discussion. The principal question involved is the observation of different technical and moral prientations that influence the conduct of the issue in the legislative process. It is possible to observe that the main focus of the projects relates to the rights and interests of the children, to those possibly benefited by the technique and to embryo reduction. Very little attention has been directed to the issues of sexual and reproductive rights and to the health of the women submitted to the new reproductive techologies.     

Hyaluronan and a cell-associated hyaluronan binding protein regulate the locomotion of ras-transformed cells

Hyaluronan (HA) and one of its cell binding sites, fibroblast hyaluronan binding protein (HABP), is shown to contribute to the regulation of 10T1/2 cell locomotion that contain an EJ-ras-metallothionein (MT-1) hybrid gene. Promotion of the ras-hybrid gene with zinc sulfate acutely stimulates, by 6-10-fold, cell locomotion. After 10 h, locomotion drops to two- to threefold above that of uninduced cells. Several observations indicate increased locomotion is partly regulated by HA. These include the ability of a peptide that specifically binds HA (HABR) to reduce locomotion, the ability of HA (0.001-0.1 micrograms/ml), added at 10-30 h after induction to stimulate locomotion back to the original, acute rate, and the ability of an mAb specific to a 56-kD fibroblast HABP to block locomotion. Further, both HA and HABP products are regulated by induction of the ras gene. The effect of exogenous HA is blocked by HABR, is dose-dependent and specific in that chondroitin sulfate or heparan have no significant effect. Stimulatory activity is retained by purified HA and lost upon digestion with Streptomyces hyaluronidase indicating that the activity of HA resides in its glycosaminoglycan chain. Uninduced cells are not affected by HA, HABR, or mAb and production of HA or HABP is not altered during the experimental period. These results suggest that ras-transformation activates an HA/HABP locomotory mechanism that forms part of an autocrine motility mechanism. Reliance of induced cells on HA/HABP for locomotion is transient and specific to the induced state.     

Partial Restoration of Macrophage Alteration from Diet-Induced Obesity in Response to Porphyromonas gingivalis Infection

Obesity is a chronic inflammatory disease that weakens macrophage innate immune response to infections. Since M1 polarization is crucial during acute infectious diseases, we hypothesized that diet-induced obesity inhibits M1 polarization of macrophages in the response to bacterial infections. Bone marrow macrophages (BMMΦ) from lean and obese mice were exposed to live Porphyromonas gingivalis (P. gingivalis) for three incubation times (1 h, 4 h and 24 h). Flow cytometry analysis revealed that the M1 polarization was inhibited after P. gingivalis exposure in BMMΦ from obese mice when compared with BMMΦ from lean counterparts. Using a computational approach in conjunction with microarray data, we identified switching genes that may differentially control the behavior of response pathways in macrophages from lean and obese mice. The two most prominent switching genes were thrombospondin 1 and arginase 1. Protein expression levels of both genes were higher in obese BMMΦ than in lean BMMΦ after exposure to P. gingivalis. Inhibition of either thrombospondin 1 or arginase 1 by specific inhibitors recovered the M1 polarization of BMMΦ from obese mice after P. gingivalis exposure. These data indicate that thrombospondin 1 and arginase 1 are important bacterial response genes, whose regulation is altered in macrophages from obese mice.     

Meclizine Inhibits Mitochondrial Respiration through Direct Targeting of Cytosolic Phosphoethanolamine Metabolism

We recently identified meclizine, an over-the-counter drug, as an inhibitor of mitochondrial respiration. Curiously, meclizine blunted respiration in intact cells but not in isolated mitochondria, suggesting an unorthodox mechanism. Using a metabolic profiling approach, we now show that treatment with meclizine leads to a sharp elevation of cellular phosphoethanolamine, an intermediate in the ethanolamine branch of the Kennedy pathway of phosphatidylethanolamine biosynthesis. Metabolic labeling and in vitro enzyme assays confirmed direct inhibition of the cytosolic enzyme CTP:phosphoethanolamine cytidylyltransferase (PCYT2). Inhibition of PCYT2 by meclizine led to rapid accumulation of its substrate, phosphoethanolamine, which is itself an inhibitor of mitochondrial respiration. Our work identifies the first pharmacologic inhibitor of the Kennedy pathway, demonstrates that its biosynthetic intermediate is an endogenous inhibitor of respiration, and provides key mechanistic insights that may facilitate repurposing meclizine for disorders of energy metabolism.     

Biothics in Brazil

In this article the authors briefly sketch the nature of Brazilian bioethics. Bioethics emerged in Brazil later than in other Western countries and the 1990's were the most important period for the spread of the discipline in the country. It is in this period that some structural elements of bioethics were established, such as research groups, regulation of Local Research Ethics Committees (Comitês Locais de Ética em Pesquisa – CEP), the creation of the National Commission of Ethics in Research with Human Beings (Comissão Nacional de Ética em Pesquisa com Seres Humanos – CONEP) and the Brazilian Bioethics Society (Sociedade Brasileira de Bioética – SBB). With regard to theoretical work, Brazilian bioethics is clearly an importer of theories from countries central to the studies of bioethics, or, in another words, countries where bioethics first emerged and was established. The most commonly used theory among Brazilian researchers is principlism     

An automated image capture and quantitation approach to identify proteins affecting tumor cell proliferation

To facilitate the characterization of proteins that negatively regulate tumor cell proliferation in vitro, the authors have implemented a high-throughput functional assay that measures S-phase progression of tumor cell lines. For 2 tumor cell lines-human melanoma A375 and human lung carcinoma A549-conditions were established using the cyclin-dependent kinase inhibitor, p27kip; the tumor suppressor p53, a kinase-inactive allele of the cell cycle-regulated serine/threonine kinase Aurora2; and the G1/S drug block, aphidicolin. For screening purposes, gene libraries were delivered by adenoviral infection. Cells were fixed and labeled by immunocytochemistry, and an automated image acquisition and analysis package on a Cellomics ArrayScanII was used to quantify the effects of these treatments on cell proliferation. The assay can be used to identify novel proteins involved in proliferation and serves as a more robust, reproducible, and sensitive alternative to enzyme-linked immunosorbent assay (ELISA)-based technologies.     

UGD1, encoding the Cryptococcus neoformans UDP-glucose dehydrogenase, is essential for growth at 37 degrees C and for capsule biosynthesis

We report the identification and disruption of the Cryptococcus neoformans var. grubii UGD1 gene encoding the UDP-glucose dehydrogenase, which catalyzes the conversion of UDP-glucose into UDP-glucuronic acid. Deletion of UGD1 led to modifications in the cell wall, as revealed by changes in the sensitivity of ugd1Delta cells to sodium dodecyl sulfate, NaCl, and sorbitol. Moreover, two of the yeast's major virulence factors-capsule biosynthesis and the ability to grow at 37 degrees C-were impaired in ugd1Delta strains. These results suggest that the UDP-dehydrogenase represents the major, and maybe only, biosynthetic pathway for UDP-glucuronic acid in C. neoformans. Consequently, deletion of UGD1 blocked not only the synthesis of UDP-glucuronic acid but also that of UDP-xylose. To differentiate the phenotype(s) associated with the UDP-glucuronic acid defect alone from those linked to the UDP-xylose defect, ugd1Delta mutants were phenotypically compared to strains from which the gene encoding UDP-xylose synthase (i.e., that required for synthesis of UDP-xylose) had been deleted. Finally, studies of strains from which one of the four CAP genes (CAP10, CAP59, CAP60, or CAP64) had been deleted revealed common cell wall phenotypes associated with the acapsular state.     

Cas3p belongs to a seven-member family of capsule structure designer proteins

The polysaccharide capsule is the main virulence factor of the basidiomycetous yeast Cryptococcus neoformans. Four genes (CAP10, CAP59, CAP60, and CAP64) essential for capsule formation have been previously identified, although their roles in the biosynthetic pathway remain unclear. A genetic and bioinformatics approach allowed the identification of six CAP64-homologous genes, named CAS3, CAS31, CAS32, CAS33, CAS34, and CAS35, in the C. neoformans genome. This gene family is apparently specific in a subclass of the basidiomycete fungi. Single as well as double deletions of these genes in all possible combinations demonstrated that none of the CAP64-homologous genes were essential for capsule formation, although the cas35Delta strains displayed a hypocapsular phenotype. The chemical structure of the glucuronomannan (GXM) produced by the CAS family deletants revealed that these genes determined the position and the linkage of the xylose and/or O-acetyl residues on the mannose backbone. Hence, these genes are all involved in assembly of the GXM structure in C. neoformans.