Disruption of dTDP-rhamnose biosynthesis modifies lipopolysaccharide core, exopolysaccharide production, and root colonization in Azospirillum brasilense

The interaction between Azospirillum brasilense and plants is not fully understood, although several bacterial surface components like exopolysaccharides (EPS), flagella, and capsular polysaccharides are required for attachment and colonization. While in other plant-bacteria associations (Rhizobium-legume, Pseudomonas-potato), lipopolysaccharides (LPS) play a key role in the establishment of an effective association, their role in the root colonization by Azospirillum had not been determined. In this study, we isolated a Tn5 mutant of A. brasilense Cd (EJ1) with an apparently modified LPS core structure, non-mucoid colony morphology, increased EPS production, and affected in maize root colonization. A 3790-bp region revealed the presence of three complete open reading frames designated rmlC, rmlB and rmlD. The beginning of a fourth open reading frame was found and designated rmlA. These genes are organized in a cluster which shows homology to the cluster involved in the synthesis of dTDP-rhamnose in other bacteria. Additionally, the analysis of the monosaccharide composition of LPSs showed a diminution of rhamnose compared to the wild-type strain.Facultad de Ciencias ExactasInstituto de Biotecnologia y Biologia Molecula

Disruption of dTDP-rhamnose biosynthesis modifies lipopolysaccharide core, exopolysaccharide production, and root colonization in Azospirillum brasilense

The interaction between Azospirillum brasilense and plants is not fully understood, although several bacterial surface components like exopolysaccharides (EPS), flagella, and capsular polysaccharides are required for attachment and colonization. While in other plant-bacteria associations (Rhizobium-legume, Pseudomonas-potato), lipopolysaccharides (LPS) play a key role in the establishment of an effective association, their role in the root colonization by Azospirillum had not been determined. In this study, we isolated a Tn5 mutant of A. brasilense Cd (EJ1) with an apparently modified LPS core structure, non-mucoid colony morphology, increased EPS production, and affected in maize root colonization. A 3790-bp region revealed the presence of three complete open reading frames designated rmlC, rmlB and rmlD. The beginning of a fourth open reading frame was found and designated rmlA. These genes are organized in a cluster which shows homology to the cluster involved in the synthesis of dTDP-rhamnose in other bacteria. Additionally, the analysis of the monosaccharide composition of LPSs showed a diminution of rhamnose compared to the wild-type strain.Facultad de Ciencias ExactasInstituto de Biotecnologia y Biologia Molecula

Enhanced osteogenic differentiation in zoledronate-treated osteoporotic patients

Bisphosphonates are well known inhibitors of osteoclast activity and thus may be employed to influence osteoblast activity. The present study was designed to evaluate the in vivo effects of zoledronic acid (ZA) on the proliferation and osteoblastic commitment of mesenchymal stem cells (MSC) in osteoporotic patients. We studied 22 postmenopausal osteoporotic patients. Densitometric, biochemical, cellular and molecular data were collected before as well as after 6 and 12 months of ZA treatment. Peripheral blood MSC-like cells were quantified by colony-forming unit fibroblastic assay; their osteogenic differentiation potential was evaluated after 3 and 7 days of induction, respectively. Circulating MSCs showed significantly increased expression levels of osteoblastic marker genes such as Runt-related transcription factor 2 (RUNX2), and Osteonectin (SPARC) during the 12 months of monitoring time. Lumbar bone mineral density (BMD) variation and SPARC gene expression correlated positively. Bone turnover marker levels were significantly lowered after ZA treatment; the effect was more pronounced for C terminal telopeptide (CTX) than for Procollagen Type 1 N-Terminal Propeptide (P1NP) and bone alkaline phosphatase (bALP). Our findings suggest a discrete anabolic activity supported by osteogenic commitment of MSCs, consequent to ZA treatment. We confirm its anabolic effects in vivo on osteogenic precursors

Intracellular Chloride Concentration Changes Modulate IL-1β Expression and Secretion in Human Bronchial Epithelial Cultured Cells

Cystic fibrosis (CF) is caused by mutations in the CFTR gene, which encodes a cAMP‐regulated chloride channel. Several cellular functions are altered in CF cells. However, it is not clear how the CFTR failure induces those alterations. We have found previously several genes differentially expressed in CF cells, including c‐Src, MUC1, MTND4, and CISD1 (CFTR‐dependent genes). Recently, we also reported the existence of several chloride‐dependent genes, among them GLRX5 and RPS27. Here, varying the intracellular chloride concentration [Cl−]i of IB3‐1 CF bronchial epithelial cells, we show that IL‐1β mRNA expression and secretion are also under Cl− modulation. The response to Cl− is biphasic, with maximal effects at 75 mM Cl−. The regulation of the IL‐1β mRNA expression involves an IL‐1β autocrine effect, since in the presence of the IL‐1β receptor antagonist IL1RN or anti‐IL‐1β blocking antibody, the mRNA response to Cl− disappeared. Similar effects were obtained with the JNK inhibitor SP600125, the c‐Src inhibitor PP2 and the IKK inhibitor III (BMS‐345541). On the other hand, the IL‐1β secretion is still modulated by Cl− in the presence of IL‐1RN, IL‐1β blocking antibody, or cycloheximide, suggesting that Cl− is affecting the IL‐1β maturation/secretion, which in turn starts an autocrine positive feedback loop. In conclusion, the Cl− anion acts as a second messenger for CFTR, modulating the IL‐1β maturation/secretion. The results also imply that, depending on its intracellular concentration, Cl− could be a pro‐inflammatory mediator.Fil: Clauzure, Mariangeles. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Valdivieso, Ángel Gabriel. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Massip Copiz, María Macarena. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Mori, Consuelo. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Dugour, Andrea Vanesa. Fundación Pablo Cassara; ArgentinaFil: Figueroa, Juan Manuel. Fundación Pablo Cassara; ArgentinaFil: Santa Coloma, Tomás Antonio. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentin

Frontal bone virtual reconstruction and geometric morphometric analysis of the mid-Pleistocene hominin KNM-OG 45500 (Olorgesailie, Kenya)

KNM-OG 45500 is a hominin fossil composed of parts of a frontal bone, left temporal bone, and cranial vault pieces. Since its discovery along the Olorgesailie Formation (Kenya) in 2003, it has been associated with the Homo erectus hypodigm. The specimen, derived from a geological context dated to ca. 900 Ka BP, has been described as a very small individual of probable female sex. However, despite its status as an important hominin specimen, it has not been used in a quantitative comparative framework because of its fragmentary condition. Here, we undertake a virtual reconstruction of the better-preserved fragment, the frontal bone. We additionally apply geometric morphometric analyses, using a geographically diverse fossil and modern human sample, in order to investigate the morphological affinities of KNM-OG 45500. Our results show that the frontal shape of KNM-OG 45500 exhibits similarities with Early Pleistocene fossils from Eurasia and Africa that are assigned to H. erectus sensu lato (s.l.). Its size, on the other hand, is notably smaller than most other Homo erectus fossils and modern humans and similar to the specimens from Dmanisi (Georgia) and to Homo naledi. Taken together, our analyses of the frontal bone suggest a taxonomic attribution of KNM-OG 45500 to H. erectus s.l. and extend even further the range of size variability associated with this taxon around 900 Ka BP

Implementación del Kaizen para la reducción de productos no conformes en la línea de mezclas secas en la Empresa Foodingredients S.A, Santa Anita 2014

El presente trabajo de investigación es de tipo cuantitativo, No - experimental, cuyo objetivo es determinar la Implementación del Kaizen para la reducción de productos no conformes en la línea de mezclas secas en la empresa Foodingredients S.A, Santa Anita. Se utilizaron los fundamentos de Hernandez, Deming, Rajadell. La muestra estuvo conformada por todos los lotes no conforme que ingresan durante el mes a quienes se les realizo el estudio. Los datos recolectados fueron procesados y analizados empleando el software SPSS versión 20. La implementación se desarrolló mediante un plan estructurado en tres fases. En la primera fase, se realizó la preparación es en donde se junta toda la información y se realiza una reunión. Siguiendo con las capacitaciones en diferentes fechas. En la segunda fase, se conformó el comité y se designó a los auditores y la aplicación de los formatos. En la tercera fase, se realizó la implementación de la herramienta de las 5S complementando con el seguimiento mediante auditorias obteniendo resultados positivos 62.8% teniendo como meta llegar al 100%. Los resultados obtenidos nos indican que la implementación es aceptable. Sin embargo, se le hizo ver a los trabajadores que la meta es llegar a obtener muy buenas condiciones y que las mejoras deberán continuar cada día dentro de la planta

Deserción y rendimiento académico en Ingeniería Industrial de la Universidad Privada del Norte, Cajamarca, 2019

La presente investigación, buscó determinar si la deserción y rendimiento académico presentan una relación significativa en los estudiantes de Ingeniería Industrial de la Universidad Privada del Norte, Cajamarca 2019. Se desarrolló una investigación básica, con diseño no experimental descriptiva transversal correlacional. Para ello se planteó la hipótesis que ambas variables presentan una asociación significativa. El método desarrollado tuvo enfoque cuantitativo. La muestra la constituyeron 25 estudiantes que abandonaron sus estudios pertenecientes a los semestres (periodo 2016 I y 2016 II). Empleando una encuesta se recolectó la información. Al tener datos no normales, empleé el estadístico Rho de Spearman cuyo valor de sig. fue 0.266, indicó, que no existe relación entre las variables de estudio. Un resultado similar, se obtuvo también, a nivel de las dimensiones: académico, económico y socio cultural.Tesi