Estudio preliminar del potencial energético de cuesco de palma y cáscara de coco en Colombia1

The use of agro-industrial waste in the energy industry has developed in recent years due to its application solving two different problems: the treatment of solid residues and the reduction of greenhouse gases. In Colombia there are many agroindustry residues; among them are coconut shells (the part that protects the white pulp) and the cuesco (shell of the fruit) of the African oil palm, both of which can be used for energy production. The authors present a bibliographical review through which it is possible to determine the energetic potential of these residues. This is the first stage of a project undertaken in 2011 by the research group “Mechanisms for clean development and energy management” of the faculty of Engineering of the Universidad Nacional de Colombia, that seeks to produce electricity through fixed bed gasification of said waste. El uso de residuos agroindustriales en la industria energética ha tomado fuerza en los últimos años debido a que su aplicación como biomasa ha solucionado dos problemas actuales: el tratamiento de residuos sólidos y la emisión de gases de efecto invernadero. En Colombia, existen varios residuos agroindustriales, entre ellos, la cáscara de coco (protege la pulpa blanca) y el cuesco de palma africana (cáscara del fruto) utilizados en la generación de energía gracias a su poder calorífico. Los autores enseñan una revisión bibliográfica que sirve de base para determinar el potencial energético de dichos residuos. Esta es la primera etapa del proyecto de investigación iniciado en el 2011 por el grupo de investigación “Mecanismos de desarrollo limpio y gestión energética de la Facultad de Ingeniería de la Universidad Nacional de Colombia”, el cual pretende producir energía eléctrica mediante la gasificación en lecho fijo de los residuos antes nombrados

Silencing of Foxp3 delays the growth of murine melanomas and modifies the tumor immunosuppressive environment

Forkhead box p3 (Foxp3) expression was believed to be specific for T-regulatory cells but has recently been described in non-hematopoietic cells from different tissue origins and in tumor cells from both epithelial and non-epithelial tissues. The aim of this study was to elucidate the role of Foxp3 in murine melanoma. The B16F10 cell line Foxp3 silenced with small interference Foxp3 plasmid transfection was established and named B16F10.1. These cells had lower levels of Foxp3 mRNA (quantitative real-time reverse transcription-polymerase chain reaction [0.235-fold]), protein (flow cytometry [0.02%]), CD25(+) expression (0.06%), cellular proliferation (trypan blue staining), and interleukin (IL)-2 production (enzyme-linked immunosorbent assay [72.35 pg/mL]) than those in B16F10 wild-type (WT) cells (P<0.05). Subcutaneous inoculation of the B16F10.1 cell line into C57BL/6 mice delayed the time of visible tumor appearance, increased the time of survival, and affected the weight of tumors, and also decreased the production of IL-10, IL-2, and transforming growth factor beta compared with mice inoculated with the B16F10 WT cell line. The B16F10.1 cells derived from tumors and free of T-cells (isolated by Dynabeads and plastic attachment) expressed relatively lower levels of Foxp3 and CD25(+) than B16F10 WT cells (P<0.05) in a time-dependent manner. The population of tumor-infiltrating lymphocytes of T CD4(+) cells (CD4(+), CD4(+)CD25(+), and CD4(+)CD25(+)Foxp3(+)) increased in a time-dependent manner (P<0.05) in tumors derived from B16F10 WT cells and decreased in tumors derived from B16F10.1 cells. Similar data were obtained from spleen cells. These results suggest that, in melanomas, Foxp3 partly induces tumor growth by modifying the immune system at the local and peripheral level, shifting the environment toward an immunosuppressive profile. Therapies incorporating this transcription factor could be strategies for cancer treatment

Physiological and behavioral effects of animal-assisted interventions for therapy dogs in pediatric oncology settings

Over the past two decades, animal-assisted interventions (AAIs), defined as the purposeful incorporation of specially trained animals in services to improve human health, have become increasingly popular in clinical settings. However, to date, there have been few rigorously-designed studies aimed at examining the impact of AAIs on therapy animals, despite a notable potential for stress. The current study measured physiological and behavioral stress indicators in therapy dogs who participated in AAI sessions in pediatric oncology settings, while also examining the psychosocial effects for patients and their parents. This manuscript describes the study’s canine stress findings. Methods: A total of 26 therapy dog-handler teams were paired with newly diagnosed children with cancer at five children’s hospitals in the United States. These teams provided regular AAI visits to the child and his/her parent(s) for a period of four months. The teams completed a demographic form, the Canine Behavioral Assessment & Research Questionnaire (C-BARQ), and a self-report survey to document the types of activities that occurred during each session. Canine saliva was also collected at five baseline time points and 20 minutes after the start of study sessions for cortisol analysis, and all study sessions were video recorded to document the dog’s behavior via an ethogram measure. Results: Data showed no significant differences in salivary cortisol levels between baseline (0.51µg/dL) and AAI sessions (0.44µg/dL), p = 0.757. Higher salivary cortisol was significantly associated with a higher number of stress behaviors per session (p = 0.039). There was a significant relationship between stress and affiliative session behaviors (pConclusions:Results show that therapy dogs did not have significantly increased physiological stress responses, nor did they exhibit significantly more stress-related behaviors than affiliative-related behaviors, while participating in AAIs in pediatric oncology settings. The significant relationship between canine cortisol and behavior, thus strengthening the argument for the use of cortisol in canine well-being research. This study discusses the importance of further investigation to confirm these findings, which may lead to enhanced canine involvement in hospital settings

Comparative and functional triatomine genomics reveals reductions and expansions in insecticide resistance-related gene families

Background: Triatomine insects are vectors of Trypanosoma cruzi, a protozoan parasite that is the causative agent of Chagas’ disease. This is a neglected disease affecting approximately 8 million people in Latin America. The existence of diverse pyrethroid resistant populations of at least two species demonstrates the potential of triatomines to develop high levels of insecticide resistance. Therefore, the incorporation of strategies for resistance management is a main concern for vector control programs. Three enzymatic superfamilies are thought to mediate xenobiotic detoxification and resistance: Glutathione Transferases (GSTs), Cytochromes P450 (CYPs) and Carboxyl/Cholinesterases (CCEs). Improving our knowledge of key triatomine detoxification enzymes will strengthen our understanding of insecticide resistance processes in vectors of Chagas’ disease. Methods and findings: The discovery and description of detoxification gene superfamilies in normalized transcriptomes of three triatomine species: Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis is presented. Furthermore, a comparative analysis of these superfamilies among the triatomine transcriptomes and the genome of Rhodnius prolixus, also a triatomine vector of Chagas’ disease, and other well-studied insect genomes was performed. The expression pattern of detoxification genes in R. prolixus transcriptomes from key organs was analyzed. The comparisons reveal gene expansions in Sigma class GSTs, CYP3 in CYP superfamily and clade E in CCE superfamily. Moreover, several CYP families identified in these triatomines have not yet been described in other insects. Conversely, several groups of insecticide resistance related enzymes within each enzyme superfamily are reduced or lacking in triatomines. Furthermore, our qRT-PCR results showed an increase in the expression of a CYP4 gene in a T. infestans population resistant to pyrethroids. These results could point to an involvement of metabolic detoxification mechanisms on the high levels of pyrethroid resistance detected in triatomines from the Gran Chaco ecoregion. Conclusions and significance: Our results help to elucidate the potential insecticide resistance mechanisms in vectors of Chagas’ disease and provide new relevant information for this field. This study shows that metabolic resistance might be a contributing cause of the high pyrethroid resistance observed in wild T. infestans populations from the Gran Chaco ecoregion, area in which although subjected to intense pyrethroid treatments, vector control has failed. This study opens new avenues for further functional studies on triatomine detoxification mechanisms.Centro Regional de Estudios GenómicosCentro de Endocrinología Experimental y Aplicad

Comparative and functional triatomine genomics reveals reductions and expansions in insecticide resistance-related gene families

Background: Triatomine insects are vectors of Trypanosoma cruzi, a protozoan parasite that is the causative agent of Chagas’ disease. This is a neglected disease affecting approximately 8 million people in Latin America. The existence of diverse pyrethroid resistant populations of at least two species demonstrates the potential of triatomines to develop high levels of insecticide resistance. Therefore, the incorporation of strategies for resistance management is a main concern for vector control programs. Three enzymatic superfamilies are thought to mediate xenobiotic detoxification and resistance: Glutathione Transferases (GSTs), Cytochromes P450 (CYPs) and Carboxyl/Cholinesterases (CCEs). Improving our knowledge of key triatomine detoxification enzymes will strengthen our understanding of insecticide resistance processes in vectors of Chagas’ disease. Methods and findings: The discovery and description of detoxification gene superfamilies in normalized transcriptomes of three triatomine species: Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis is presented. Furthermore, a comparative analysis of these superfamilies among the triatomine transcriptomes and the genome of Rhodnius prolixus, also a triatomine vector of Chagas’ disease, and other well-studied insect genomes was performed. The expression pattern of detoxification genes in R. prolixus transcriptomes from key organs was analyzed. The comparisons reveal gene expansions in Sigma class GSTs, CYP3 in CYP superfamily and clade E in CCE superfamily. Moreover, several CYP families identified in these triatomines have not yet been described in other insects. Conversely, several groups of insecticide resistance related enzymes within each enzyme superfamily are reduced or lacking in triatomines. Furthermore, our qRT-PCR results showed an increase in the expression of a CYP4 gene in a T. infestans population resistant to pyrethroids. These results could point to an involvement of metabolic detoxification mechanisms on the high levels of pyrethroid resistance detected in triatomines from the Gran Chaco ecoregion. Conclusions and significance: Our results help to elucidate the potential insecticide resistance mechanisms in vectors of Chagas’ disease and provide new relevant information for this field. This study shows that metabolic resistance might be a contributing cause of the high pyrethroid resistance observed in wild T. infestans populations from the Gran Chaco ecoregion, area in which although subjected to intense pyrethroid treatments, vector control has failed. This study opens new avenues for further functional studies on triatomine detoxification mechanisms.Centro Regional de Estudios GenómicosCentro de Endocrinología Experimental y Aplicad

Nitrate and nitrite in drinking water affect antioxidant enzymes in erythrocytes of rats

The present study evaluated the effect of short term intake of nitrite and nitrate drinking water on the antioxidant system and membrane damage of rat erythrocytes. Wistar rats were randomly divided into three groups as follows; the group I received only distilled water ad libitum; the group II was given water with nitrate (a dose of 124 mg/kg of nitrate-nitrogen) as drinking water and the group III was given nitrites dissolved in distilled water in a dose of 150 mg/kg for 7 days. At the end of the study, group III rats showed a significant decrease in activities of glutathione peroxidase (GPx), glucose 6-phosphate dehydrogenase (G6PDH) and catalase (CAT), while in group II rats, the activity of GPx and CAT were significantly reduced, but no significant changes in glutathione reductase activity and peroxynitrite levels were observed. On the other hand, malondialdehyde (MDA) was increased in both groups with respect to group I. Also, our major results indicate that all treatments changed methemoglobin levels and osmotic fragility in comparison to group I rats. The intensity of alterations was found more severe in rats of group III, followed by rats of group II. It can be concluded from these observations that nitrate or nitrite leads to alterations in the erythrocytes antioxidant defense status mainly throughout NADPH relate enzymes

Changes in an Enzyme Ensemble During Catalysis Observed by High Resolution XFEL Crystallography

Enzymes populate ensembles of structures with intrinsically different catalytic proficiencies that are difficult to experimentally characterize. We use time-resolved mix-and-inject serial crystallography (MISC) at an X-ray free electron laser (XFEL) to observe catalysis in a designed mutant (G150T) isocyanide hydratase (ICH) enzyme that enhances sampling of important minor conformations. The active site exists in a mixture of conformations and formation of the thioimidate catalytic intermediate selects for catalytically competent substates. A prior proposal for active site cysteine charge-coupled conformational changes in ICH is validated by determining structures of the enzyme over a range of pH values. A combination of large molecular dynamics simulations of the enzyme in crystallo and timeresolved electron density maps shows that ionization of the general acid Asp17 during catalysis causes additional conformational changes that propagate across the dimer interface, connecting the two active sites. These ionization-linked changes in the ICH conformational ensemble permit water to enter the active site in a location that is poised for intermediate hydrolysis. ICH exhibits a tight coupling between ionization of active site residues and catalysis-activated protein motions, exemplifying a mechanism of electrostatic control of enzyme dynamics

Comparative and functional triatomine genomics reveals reductions and expansions in insecticide resistance-related gene families

Background: Triatomine insects are vectors of Trypanosoma cruzi, a protozoan parasite that is the causative agent of Chagas’ disease. This is a neglected disease affecting approximately 8 million people in Latin America. The existence of diverse pyrethroid resistant populations of at least two species demonstrates the potential of triatomines to develop high levels of insecticide resistance. Therefore, the incorporation of strategies for resistance management is a main concern for vector control programs. Three enzymatic superfamilies are thought to mediate xenobiotic detoxification and resistance: Glutathione Transferases (GSTs), Cytochromes P450 (CYPs) and Carboxyl/Cholinesterases (CCEs). Improving our knowledge of key triatomine detoxification enzymes will strengthen our understanding of insecticide resistance processes in vectors of Chagas’ disease. Methods and findings: The discovery and description of detoxification gene superfamilies in normalized transcriptomes of three triatomine species: Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis is presented. Furthermore, a comparative analysis of these superfamilies among the triatomine transcriptomes and the genome of Rhodnius prolixus, also a triatomine vector of Chagas’ disease, and other well-studied insect genomes was performed. The expression pattern of detoxification genes in R. prolixus transcriptomes from key organs was analyzed. The comparisons reveal gene expansions in Sigma class GSTs, CYP3 in CYP superfamily and clade E in CCE superfamily. Moreover, several CYP families identified in these triatomines have not yet been described in other insects. Conversely, several groups of insecticide resistance related enzymes within each enzyme superfamily are reduced or lacking in triatomines. Furthermore, our qRT-PCR results showed an increase in the expression of a CYP4 gene in a T. infestans population resistant to pyrethroids. These results could point to an involvement of metabolic detoxification mechanisms on the high levels of pyrethroid resistance detected in triatomines from the Gran Chaco ecoregion. Conclusions and significance: Our results help to elucidate the potential insecticide resistance mechanisms in vectors of Chagas’ disease and provide new relevant information for this field. This study shows that metabolic resistance might be a contributing cause of the high pyrethroid resistance observed in wild T. infestans populations from the Gran Chaco ecoregion, area in which although subjected to intense pyrethroid treatments, vector control has failed. This study opens new avenues for further functional studies on triatomine detoxification mechanisms.Centro Regional de Estudios GenómicosCentro de Endocrinología Experimental y Aplicad