Expression, Characterization and Synergistic Interactions of Myxobacter Sp. AL-1 Cel9 and Cel48 Glycosyl Hydrolases

The soil microorganism Myxobacter Sp. AL-1 regulates in a differential manner the production of five extracellular cellulases during its life cycle. The nucleotide sequence of a cel9-cel48 cluster from the genome of this microorganism was recently obtained. Cel48 was expressed in Escherichia coli to generate a His6-Cel48 protein and the biochemical properties of the pure protein were determined. Cel48 was more efficient in degrading acid-swollen avicel (ASC) than carboxymethylcellulose (CMC). On the other hand, cel9 was expressed in Bacillus subtilis from an IPTG-inducible promoter. Zymogram analysis showed that after IPTG-induction, Cel9 existed in both the cell fraction and the culture medium of B. subtilis and the secreted protein was purified to homogeneity by FPLC-ionic exchange chromatography. The exocellobiohydrolase Cel48 showed a synergism of 1.68 times with the endocellulase Cel9 during ASC degradation using an 8.1-fold excess of Cel48 over Cel9. Western blot analysis revealed that both proteins were synthesized and secreted to the culture medium of Myxobacter Sp. AL-1. These results show that the cel9-cel48 cluster encodes functional endo- and exo-acting cellulases that allows Myobacter Sp. AL-1 to hydrolyse cellulose

Restricción del crecimiento intrauterino como factor de riesgo para malformaciones congénitas

Indexación: ScieloAntecedentes: La restricción del crecimiento intrauterino (RCIU) se estima que está presente en el 5% de los nacimientos y es la manifestación de procesos aberrantes que impiden el desarrollo normal del feto. Objetivos: Estimar la frecuencia de esta patología en la maternidad del Hospital Clínico de la Universidad de Chile. Obtener la tasa prevalencia al nacimiento de malformaciones congénitas (MFC) y comparar la frecuencia en recién nacidos pequeños (PEG) con los adecuados (AEG) y grandes (GEG) para la edad gestacional. Método: Se estudian todos los nacimientos, vivos y mortinatos, ocurridos entre enero de 1997 a diciembre de 2008, contenidos en la base de datos del ECLAMC (Estudio Colaborativo Latino Americano de Malformaciones Congénitas) desde 1969 a la fecha. Se excluyen los recién nacidos con malformaciones como hidrocefalia, anencefalia e hidrops, que por sus características dificultan la posibilidad de clasificación en PEG, AEG o GEG. Resultados: 10,1% de los nacimientos del período eran PEG. Entre los nacidos vivos 10% fueron PEG, mientras que 33,5% de los mortinatos eran PEG (p<0,05). Eran malformados el 12,9% de los PEG, 8,5% de los AEG y 9,3% de los GEG (p<0,05). La tasa global de malformaciones fue de 9,5%; en NV el 9,4% y en mortinatos el 33%. Conclusión: El RCIU es un factor que aumenta el riesgo de mortalidad fetal tardía y de presentar malformaciones congénitas.Background: Fetal growth restriction (FGR) is the result of anomalies that prevent the normal development of the fetus, it is present in about the 5% of births. Objectives: To estímate the frequency of FGR in the Clini-cal Hospital of the University of Chile. To estímate the congenital malformation prevalence rate at birth and compare it among small (SGE), adequate (AGE) and large (LGE) newborns according their gestational age. Methods: All live births and stillbirths included in the ECLAMC (Estudio Colaborativo Latino Americano de Malformaciones Congénitas) registered from January 1997 and December 2008 were considered. Newborns with congenital malformations that modified per se the size of the child, like hydrocephaly anencephaly and hydrops were excluded. Results: 10.1% of newborns were SGE. Among live births 10% were SGE instead of the 33.5% found in stillbirths (p<0.05). Congenital malformation rate at birth was 12.9% in SGE, 8.5% in AGE and 9.3% in LGE newborns (p<0.05). The global congenital malformation prevalence rate at birth was 9.5%; 9.4% in live newborns and 33% in stillbirth. Conclusión: The FGR increase the risk of late fetal mortality and congenital anomalies.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-75262009000600008&nrm=is

Agronomic and phytosanitary characterization of tomato production in the Comiteca- Tojolabal Plateau

Objective: Agronomic and phytosanitary characterization of tomato production units of the Meseta Comiteca-Tojolabal, Chiapas. Design/methodology/approach: Seventy-six tomato fields were sampled and the same number of surveys were applied to their respective farmers regarding agronomic practices and phytosanitary status of the crop. Results: Tomatoes are grown in shade-houses, on plots that mostly do not exceed half a hectare. The most common practices are crop rotation, one tomato cycle per year, incorporation of previous crop residues, and fertilization every 5-8 days. For phytosanitary management, foliar sprays are commonly performed every 5-8 days. Sixty seven percent of producers pre-treat seedlings to prevent diseases and pests. Ninety five percent perform applications of bactericides and fungicides to the roots, during the first 45 days of the crop. The most important pests and diseases are the whitefly, thrips, Bactericera sp, late blight, virus diseases and wilts. The incidence of diseased plants due to root and vascular diseases ranges from zero to 38%. However, low values ​​were more frequent. The severity of wilting at the regional level is low, since 90 % of the evaluated plants did not present symptoms. Limitations on study/implications: This is the first work that describes agronomic and phytosanitary aspects of tomato cultivation in this region. More research is required with this approach; this work will be the basis for further studies. Findings/conclusions: Most of the tomato farms are less than 0.5 ha, with an intensive phytosanitary treatment with pesticides. In addition to chemical control, the cultural practices used may be contributing to a low incidence and severity of soil-borne diseases. The most important crop diseases are late blight and virosis.Objective: To characterize the agronomic and phytosanitary aspects of the tomato production units of the Comiteca-Tojolabal Plateau, Chiapas, Mexico.Design/Methodology/Approach: A random sampling of n=76 tomato fields was performed; agronomic practice surveys were applied to their respective farmers, and the phytosanitary status of each site was evaluated.Results: Tomatoes are grown in shade houses, in plots that mostly do not exceed 0.5 ha. The most common practices are crop rotation, one tomato cycle per year, incorporation of previous crop residues, and fertilization every 5-8 days. For phytosanitary management, foliar sprays are usually performed every 5-8 days. In order to prevent diseases and pests, 67% of producers pre-treat seedlings and 95% apply bactericides and fungicides to the roots during the first 45 days of the crop. The most important pests and diseases are whitefly, thrips, Bactericera sp., late blight, virosis, and wilt. The percentage of plants that suffer from root and vascular diseases ranges from 0-38%. However, low values were more frequent. The regional severity of wilting is low, since 90% of the plants evaluated did not present symptoms. Study Limitations/Implications: This is the first work to describe the agronomic and phytosanitary aspects of tomato cultivation in this region. Additional research with this approach is required and this work will be the basis for further studies.Findings/Conclusions: Most of the tomato farms have less than 0.5 ha and their farmers carry out intensive phytosanitary management with pesticides. In addition to chemical control, the cultural practices used may contribute to a low incidence and severity of soil-borne diseases. The most important crop diseases are late blight and virosis

Early and Delayed Hypersensitivity Reactions to Paclitaxel: Desensitization as A challenge

Reacciones de hipersensibilidad secundarias a taxanos y su tratamiento a base de desensibilización

A high concentration of TGF-β correlates with opportunistic infection in liver and kidney transplantation

Transforming growth factor-β (TGF-β) has been associated with numerous human infections, but its role in the occurrence of opportunistic infection (OI) after solid organ transplantation remains unexplored. This study aimed to assess the utility of the TGF-β following in vitro stimulation of whole peripheral blood (WPB) as a surrogate biomarker of post-transplant OI in a cohort of liver and kidney recipients. Thirty liver and thirty-one kidney transplant recipients were recruited to be prospectively monitored for one-year post-transplantation. Enzyme-linked immunosorbent assay (ELISA) was performed to calculate IFN-γ, IL-17, IL-10 and TGF-β concentration in the supernatant from the activated WPB. Recipients showed higher TGF-β concentrations compared to IFN-γ, IL-17, IL-10 at baseline, although these differences were not significant between INF and NoINF. However, recipients who developed an OI within the first sixth months had a higher concentration of TGF-β than those without OI. A concentration of TGF-β > 363.25 pg/ml in liver and TGF-β > 808.51 pg/ml in kidney recipients were able to stratify patients at high risk of OI with a sensitivity and specificity above 70% in both types of solid organ transplantations. TGF-β could provide valuable information for the management of liver and kidney recipients at risk of post-transplant infection.Our work was possible thanks to the support and funding obtained from the “Instituto de Salud Carlos III (ISCIII)”, Spanish Ministry of Health (Grant Number PI15/01370 and P19/01194); and co-funding by the European Union from the European Regional Development Fund (ERDF) with the principle of “A manner to build Europe”

Desarrollo de estrategias para el manejo sostenible de la Altillanura Colombiana

Los Llanos Orientales de Colombia cubren cerca de 26 millones de hectáreas de las cuales un 53% (14 millones) pertenecen a la Orinoquia bien drenada (terrazas aluviales Altillanura plana y Altillanura disectada) Sin embargo el gran potencial agropecuario lo constituyen cerca de 46 millones de hectáreas constituidas por las terrazas y Altillanura plana actualmente subutilizadas en una ganadería extensiva con pastos de baja calidad nutricional Los suelos de estas sabanas de la Orinoquia se caracterizan por su alta acidez baja fertilidad química baja actividad biológica y débil estructura física que los hace fuertemente susceptibles a erosión y a compactación Aun así estos ecosistemas presentan ventajas comparativas con relación a otras zonas de producción agropecuaria del País por su abundante y buena distribución de lluvias y topografía relativamente plana que facilita la utilización racional de la mecanización como practica agrícola constructora de suelos y no degradativa

KIR+ CD8+ T Lymphocytes in Cancer Immunosurveillance and Patient Survival: Gene Expression Profiling

Killer-cell immunoglobulin-like receptors (KIR) are molecules expressed by the most important cells of the immune system for cancer immune vigilance, natural killer (NK) and effector T cells. In this manuscript we study the role that cytotoxic CD8+ T cells expressing KIR receptors could play in cancer immune surveillance. With this objective, frequencies of different KIR+ CD8+ T cell subsets are correlated with the overall survival of patients with melanoma, ovarian and bladder carcinomas. In addition, the gene expression profile of KIR+ CD8+ T cell subsets related to the survival of patients is studied with the aim of discovering new therapeutic targets, so that the outcome of patients with cancer can be improved. Killer-cell immunoglobulin-like receptors (KIR) are expressed by natural killer (NK) and effector T cells. Although KIR+ T cells accumulate in oncologic patients, their role in cancer immune response remains elusive. This study explored the role of KIR+CD8+ T cells in cancer immunosurveillance by analyzing their frequency at diagnosis in the blood of 249 patients (80 melanomas, 80 bladder cancers, and 89 ovarian cancers), their relationship with overall survival (OS) of patients, and their gene expression profiles. KIR2DL1+ CD8+ T cells expanded in the presence of HLA-C2-ligands in patients who survived, but it did not in patients who died. In contrast, presence of HLA-C1-ligands was associated with dose-dependent expansions of KIR2DL2/S2+ CD8+ T cells and with shorter OS. KIR interactions with their specific ligands profoundly impacted CD8+ T cell expression profiles, involving multiple signaling pathways, effector functions, the secretome, and consequently, the cellular microenvironment, which could impact their cancer immunosurveillance capacities. KIR2DL1/S1+ CD8+ T cells showed a gene expression signature related to efficient tumor immunosurveillance, whereas KIR2DL2/L3/S2+CD8+ T cells showed transcriptomic profiles related to suppressive anti-tumor responses. These results could be the basis for the discovery of new therapeutic targets so that the outcome of patients with cancer can be improved

Sperm from Hyh Mice Carrying a Point Mutation in αSNAP Have a Defect in Acrosome Reaction

Hydrocephalus with hop gait (hyh) is a recessive inheritable disease that arose spontaneously in a mouse strain. A missense mutation in the Napa gene that results in the substitution of a methionine for isoleucine at position 105 (M105I) of αSNAP has been detected in these animals. αSNAP is a ubiquitous protein that plays a key role in membrane fusion and exocytosis. In this study, we found that male hyh mice with a mild phenotype produced morphologically normal and motile sperm, but had a strongly reduced fertility. When stimulated with progesterone or A23187 (a calcium ionophore), sperm from these animals had a defective acrosome reaction. It has been reported that the M105I mutation affects the expression but not the function of the protein. Consistent with an hypomorphic phenotype, the testes and epididymides of hyh mice had low amounts of the mutated protein. In contrast, sperm had αSNAP levels indistinguishable from those found in wild type cells, suggesting that the mutated protein is not fully functional for acrosomal exocytosis. Corroborating this possibility, addition of recombinant wild type αSNAP rescued exocytosis in streptolysin O-permeabilized sperm, while the mutant protein was ineffective. Moreover, addition of recombinant αSNAP. M105I inhibited acrosomal exocytosis in permeabilized human and wild type mouse sperm. We conclude that the M105I mutation affects the expression and also the function of αSNAP, and that a fully functional αSNAP is necessary for acrosomal exocytosis, a key event in fertilization

Perspectivas de la empresa y la economía mexicana frente a la reestructuración productiva

1 archivo PDF (404 páginas)Este texto se presenta una reflexión de investigadores de la UAM, así como de otras Instituciones de Educación Superior respecto al marco en el que se han desenvuelto las empresas mexicanas en los últimos años, así como del desarrollo en algunos de sus sistemas organizacionales. PALABRAS CLAVE: Mexico Economic policy 1970-1994