A Latin American Perspective to Agricultural Ethics

The mixture of political, social, cultural and economic environments in Latin America, together with the enormous diversity in climates, natural habitats and biological resources the continent offers, make the ethical assessment of agricultural policies extremely difficult. Yet the experience gained while addressing the contemporary challenges the region faces, such as rapid urbanization, loss of culinary and crop diversity, extreme inequality, disappearing farming styles, water and land grabs, malnutrition and the restoration of the rule of law and social peace, can be of great value to other regions in similar latitudes, development processes and social problems. This chapter will provide a brief overview of these challenges from the perspective of a continent that is exposed to the consequences of extreme inequality in multiple dimensions and conclude by arguing for the need to have a continuous South-South dialogue on the challenges of establishing socially and environmentally sustainable food systems

Mujeres y cultura en la Argentina del siglo XIX

Este libro es el resultado de buscar y rebuscar, acuciadas en un primer momento por una natural curiosidad hacia el siglo XIX, en el baúl de nuestras abuelas o incluso bisabuelas. Y nos encontramos no sólo con el pasado sino con nuestro pasado, rico, complejo, sorprendente en su infinita variedad de hallazgos. Experimentamos un sentimiento de ternura por esas mujeres y de profunda solidaridad ante el esfuerzo que realizaron, muchas veces en condiciones inhóspitas, incomprendidas por sus contemporáneos, varones y mujeres. No sólo mujeres con nombre propio sino mujeres generalmente anónimas forman una parte esencial de la historia no contada, oculta(da) en el polvo acumulado durante el transcurso de los años. Nuestra tarea, nuestra pasión es desenvolverla, descubrirla, deconstruirla. Un acto compartido entre muchas mujeres y algunos varones. En mayor o menor grado, cada artículo en Mujeres y cultura en la Argentina del siglo XIXcontribuye a este fin y también al de la construcción –la re-construcción- de la historia de mujeres en la Argentina. Hay todavía mucho por revolver en esos arcones. Sabemos que hay nombres escondidos todavía en publicaciones que debemos encontrar. Nombres de mujeres, sus labores, que han sido muy poco investigadas o que sencillamente desconocemos. Se trata de hacer visible una producción ignorada y una tradición desdibujada

Evaluation of Brucella abortus Phosphoglucomutase (pgm) Mutant as a New Live Rough-Phenotype Vaccine

Brucella abortus S19 is the vaccine most frequently used against bovine brucellosis. Although it induces good protection levels, it cannot be administered to pregnant cattle, revaccination is not advised due to interference in the discrimination between infected and vaccinated animals during immune-screening procedures, and the vaccine is virulent for humans. Due to these reasons, there is a continuous search for new bovine vaccine candidates that may confer protection levels comparable to those conferred by S19 but without its disadvantages. A previous study characterized the phenotype associated with the phosphoglucomutase (pgm) gene disruption in Brucella abortus S2308, as well as the possible role for the smooth lipopolysaccharide (LPS) in virulence and intracellular multiplication in HeLa cells (J. E. Ugalde, C. Czibener, M. F. Feldman, and R. A. Ugalde, Infect. Immun. 68:5716-5723, 2000). In this report, we analyze the protection, proliferative response, and cytokine production induced in BALB/c mice by a Δpgm deletion strain. We show that this strain synthesizes O antigen with a size of approximately 45 kDa but is rough. This is due to the fact that the Δpgm strain is unable to assemble the O side chain in the complete LPS. Vaccination with the Δpgm strain induced protection levels comparable to those induced by S19 and generated a proliferative splenocyte response and a cytokine profile typical of a Th1 response. On the other hand, we were unable to detect a specific anti-O-antigen antibody response by using the fluorescence polarization assay. In view of these results, the possibility that the Δpgm mutant could be used as a vaccination strain is discussed

Astrocyte Apoptosis and HIV Replication Are Modulated in Host Cells Coinfected with Trypanosoma cruzi

The protozoan Trypanosoma cruzi is the etiological agent of Chagas disease. In immunosuppressed individuals, as it occurs in the coinfection with human immunodeficiency virus (HIV), the central nervous system may be affected. In this regard, reactivation of Chagas disease is severe and often lethal, and it accounts for meningoencephalitis. Astrocytes play a crucial role in the environment maintenance of healthy neurons; however, they can host HIV and T. cruzi. In this report, human astrocytes were infected in vitro with both genetically modified-pathogens to express alternative fluorophore. As evidenced by fluorescence microscopy and flow cytometry, HIV and T. cruzi coexist in the same astrocyte, likely favoring reciprocal interactions. In this context, lower rates of cell death were observed in both T. cruzi monoinfected-astrocytes and HIV-T. cruzi coinfection in comparison with those infected only with HIV. The level of HIV replication is significantly diminished under T. cruzi coinfection, but without affecting the infectivity of the HIV progeny. This interference with viral replication appears to be related to the T. cruzi multiplication rate or its increased intracellular presence but does not require their intracellular cohabitation or infected cell-to-cell contact. Among several Th1/Th2/Th17 profile-related cytokines, only IL-6 was overexpressed in HIV-T. cruzi coinfection exhibiting its cytoprotective role. This study demonstrates that T. cruzi and HIV are able to coinfect astrocytes thus altering viral replication and apoptosis

Inactive trans-Sialidase Expression in iTS-null Trypanosoma cruzi Generates Virulent Trypomastigotes

Disclosing virulence factors from pathogens is required to better understand the pathogenic mechanisms involved in their interaction with the host. In the case of Trypanosoma cruzi several molecules are associated with virulence. Among them, the trans-sialidase (TS) has arisen as one of particular relevance due to its effect on the immune system and involvement in the interaction/invasion of the host cells. The presence of conserved genes encoding for an inactive TS (iTS) isoform is puzzlingly restricted to the genome of parasites from the Discrete Typing Units TcII, TcV, and TcVI, which include highly virulent strains. Previous in vitro results using recombinant iTS support that this isoform could play a different or complementary pathogenic role to that of the enzymatically active protein. However, direct evidence involving iTS in in vivo pathogenesis and invasion is still lacking. Here we faced this challenge by transfecting iTS-null parasites with a recombinant gene that allowed us to follow its expression and association with pathological events. We found that iTS expression improves parasite invasion of host cells and increases their in vivo virulence for mice as shown by histopathologic findings in heart and skeletal muscle

Parasite DTU evolution model proposed.

<p>Considering the previously proposed evolution models <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058967#pone.0058967-Zingales1" target="_blank">[3]</a> together with data reported here, an evolution model is drawn where the acquisition of the <i>iTS</i> gene by a single mutation event by TcII places TcI and TcII as the only ancestors for all the other DTUs. A single hybridization event of TcIII and TcII derivates in TcV and VI as previously proposed.</p

Chromatograms from the region flanking the T/C SNP.

<p>Sequencing examples from parasites belonging to the six DTUs are shown. Black arrow points T and C nucleotides in TcII, TcV and TcVI PCR products. Empty arrow points the same position in TcI, TcIII and TcIV amplicons, where only T was observed. Star indicates a T/G SNP (K in IUPAC code) present in all tested parasites.</p

Quantification of <i>aTS</i> and <i>iTS</i> in parasites representing high and low TS activity producers.

<p>a) Parasites correspond to low (TcI) and high (TcII and TcVI) TS activity producer stocks as described by Risso <i>et al</i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058967#pone.0058967-Risso3" target="_blank">[37]</a>.</p><p>Parasite DNA was subjected to quantitative real time PCR and <i>aTS</i>/<i>iTS</i> presence was determined by using probes labeled with reporter dyes. Gene number per haploid genome was determined by Ct comparison with that obtained for the <i>pvdh</i> single copy gene. Ct: cycle of threshold; ND: not detectable.</p

UPGMA tree based on TS genes sequence alignment (with ambiguous states).

<p>Each circle grouped all 38 <i>T. cruzi</i> strains in their respective previous assigned DTU, except CAN III and 3.1 that were previously assigned to TcIV. Significant bootstrap values for TcI, TcIII and TcIV are reported, bootstrap values for other DTUs were <50.</p