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.     

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.     

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     

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.     

Characterization of mutations in the GTP-binding domain of IF2 resulting in cold-sensitive growth of Escherichia coli

The infB gene encodes translation initiation factor IF2. We have determined the entire sequence of infB from two cold-sensitive Escherichia coli strains IQ489 and IQ490. These two strains have been isolated as suppressor strains for the temperature-sensitive secretion mutation secY24. The mutations causing the suppression phenotype are located within infB. The only variations from the wild-type (wt) infB found in the two mutant strains are a replacement of Asp409 with Glu in strain IQ489 and an insertion of Gly between Ala421 and Gly422 in strain IQ490. Both positions are located in the GTP-binding G-domain of IF2. A model of the G-domain of E.coli IF2 is presented in. Physiological quantities of the recombinant mutant proteins were expressed in vivo in E.coli strains from which the chromosomal infB gene has been inactivated. At 42 degrees C, the mutants sustained normal cell growth, whereas a significant decrease in growth rate was found at 25 degrees C for both mutants as compared to wt IF2 expressed in the control strain. Circular dichroism spectra were recorded of the wt and the two mutant proteins to investigate the structural properties of the proteins. The spectra are characteristic of alpha-helix dominated structure, and reveal a significant different behavior between the wt and mutant IF2s with respect to temperature-induced conformational changes. The temperature-induced conformational change of the wt IF2 is a two-state process. In a ribosome-dependent GTPase assay in vitro the two mutants showed practically no activity at temperatures below 10 degrees C and a reduced activity at all temperatures up to 45 degrees C, as compared to wt IF2. The results indicate that the amino acid residues, Asp409 and Gly422, are located in important regions of the IF2 G-domain and demonstrate the importance of GTP hydrolysis in translation initiation for optimal cell growth.     

UV and X-ray sensitivity of Candida albicans laboratory strains and mutants having chromosomal alterations

Utilization of L-sorbose, D-arabinose or primary fluconazole resistance in Candida albicans are controlled by copy number of specific chromosomes. On the other hand, spontaneous morphological mutants have a wide range of chromosomal alterations. We have investigated the UV and X-ray sensitivity of these mutants, as well as C. albicans laboratory strains. While L-sorbose utilizing mutants had normal sensitivities, a large subclass of D-arabinose utilizing mutants was abnormally sensitive to UV. Spontaneous morphological mutants responded differently, an expected result because of the heterogeneous nature of their electrophoretic karyotypes. We suggest that the differences in UV and X-ray sensitivity are due to gene imbalance caused by some chromosomal alterations. In this respect, the radiation sensitivity is similar to other features impaired by changes in chromosomes, but is unlike the acquisition of the ability to utilize alternative nutrients or the acquisition of resistance to fluconazole. Our studies also revealed that strains of C. albicans heterozygous for the mating type loci exhibited the same X-ray sensitivity as homozygous or hemizygous strains, a finding which is in contrast to the properties of Saccharomyces cerevisiae, where heterozygous strains are more resistant. This feature of C. albicans strains may be indicative of an inefficient repair system that may be related to inefficiency of mating.     

Influence of inoculum preparation on the growth of Penicillium chrysogenum

AIMS: The influence of the spore preparation on subsequent fungal growth of Penicillium chrysogenum was assessed. METHODS AND RESULTS: The influence of four factors [the nature of the diluting solution (physiological water and physiological water added with Tween-80), the age of the sporulating culture (4, 8 and 12 days), the strain (737, 738 and 740) and the inoculum size (102, 103, 104 and 105 spores ml(-1)] on two responses (i.e. the radial growth rate, mu, and the lag time, lambda) was studied using an experimental screening methodology. CONCLUSIONS: The main conclusion was the strong effect of the inoculum size on lambda. In contrast, the diluting solution had no effect on both the experimental responses. In order to obtain the highest growth rates, it is recommended to use 4-day-old sporulating cultures with an inoculum size of 102 spores ml(-1). SIGNIFICANCE AND IMPACT OF THE STUDY: There is a need for standardizing spore preparation in predictive mycology. The screening methodology is a powerful tool to determine the influence of qualitative and quantitative factors on various biological responses and can be applied widely in microbiology.