Purificación y estructura primaria de una lectina aislada de semillas de Buddleja coriácea

Se purificó una lectina aislada de semillas de Buddleja coriacea R. (“colle negro”, Buddlejaceae) mediante cromatografía de exclusión molecular y cromatografía líquida de alta eficiencia de fase reversa (HPLC). El análisis en SDS-PAGE de dos dimensiones demostró que la lectina purificadaes homogénea porque aparece como un único spot proteico correspondiendo a ~12 kDa con un punto isoeléctrico de 5.3. Mediante espectrometría de masa (MALDI-TOF) se confirmó el peso molecular de la lectina mostrando una masa de 12,630.1405 Da. El análisis de aminoácidos reveló que la lectina de Buddleja coriacea R. (BCL) es de carácter ácido y altamente hidrofóbico (21% de residuos ácidos y 41% de hidrofóbicos). La secuencia completa de aminoácidos señaló que BCL contiene 119 residuos. El estudio comparativo con otras lectinas mostró que BCL tiene alta similaridad con lectinas de Cratylia mollis (Leguminosae, 96,60% de homología) y Cratylia argentea (89,90% de homología). Según el árbol filogenético, BCL presentó una secuencia evolutiva de ~2000 nucleótidos con respecto a la lectina extraída de semillas de Cratylia mollis. BCL exhibió aglutinación de los grupos sanguíneos humanos “A”, “B” y “AB” Rh (+) con una concentración mínima de hemaglutinación de 1,3 µg/mL; la actividad hemaglutinante fue inhibida por la D-lactosa y D-manosa (0,048 y 0,097 mM,respectivamente) y por los agentes quelantes EDTA (25 mM) y EGTA (25 mM).Palabras clave: Buddleja coriacea, lectina, BCL, secuencia de aminoácidos, árbol filogenético

PhTX-II a basic myotoxic phospholipase A2 from Porthidium Hyoprora snake venom, pharmacological characterization and amino acid sequence by mass spectrometry

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOA monomeric basic PLA2 (PhTX-II) of 14149.08 Da molecular weight was purified to homogeneity from Porthidium hyoprora venom. Amino acid sequence by in tandem mass spectrometry revealed that PhTX-II belongs to Asp49 PLA2 enzyme class and displays conserved domains as the catalytic network, Ca2+-binding loop and the hydrophobic channel of access to the catalytic site, reflected in the high catalytic activity displayed by the enzyme. Moreover, PhTX-II PLA2 showed an allosteric behavior and its enzymatic activity was dependent on Ca2+. Examination of PhTX-II PLA2 by CD spectroscopy indicated a high content of alpha-helical structures, similar to the known structure of secreted phospholipase IIA group suggesting a similar folding. PhTX-II PLA2 causes neuromuscular blockade in avian neuromuscular preparations with a significant direct action on skeletal muscle function, as well as, induced local edema and myotoxicity, in mice. The treatment of PhTX-II by BPB resulted in complete loss of their catalytic activity that was accompanied by loss of their edematogenic effect. On the other hand, enzymatic activity of PhTX-II contributes to this neuromuscular blockade and local myotoxicity is dependent not only on enzymatic activity. These results show that PhTX-II is a myotoxic Asp49 PLA2 that contributes with toxic actions caused by P. hyoprora venom.A monomeric basic PLA2 (PhTX-II) of 14149.08 da molecular weight was purified to homogeneity from Porthidium hyoprora venom. Amino acid sequence by in tandem mass spectrometry revealed that PhTX-II belongs to Asp49 PLA2 enzyme class and displays conserved domains as the catalytic network, Ca2+-binding loop and the hydrophobic channel of access to the catalytic site, reflected in the high catalytic activity displayed by the enzyme. Moreover, PhTX-II PLA2 showed an allosteric behavior and its enzymatic activity was dependent on Ca2+. Examination of PhTX-II PLA2 by CD spectroscopy indicated a high content of alpha-helical structures, similar to the known structure of secreted phospholipase IIA group suggesting a similar folding. PhTX-II PLA2 causes neuromuscular blockade in avian neuromuscular preparations with a significant direct action on skeletal muscle function, as well as, induced local edema and myotoxicity, in mice. The treatment of PhTX-II by BPB resulted in complete loss of their catalytic activity that was accompanied by loss of their edematogenic effect. On the other hand, enzymatic activity of PhTX-II contributes to this neuromuscular blockade and local myotoxicity is dependent not only on enzymatic activity. These results show that PhTX-II is a myotoxic Asp49 PLA2 that contributes with toxic actions caused by P. hyoprora venom630773097FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2009/51207-

The Hazards of Monitoring Ecosystem Ocean Health in the Gulf of Mexico: A Mexican Perspective

Ecological services provided by the Gulf of Mexico constitute vital assets for the socioeconomic development of the USA, Mexico, and Cuba. This ecosystem houses vast biodiversity and significant fossil fuel reserves. However, its ecological stability and resilience have been jeopardized by anthropogenic disturbances. Massive oil spills (Ixtoc-I, 1979; Deepwater Horizon, 2010) caused severe environmental injuries and unveiled the vulnerability of coastal and deep-sea habitats. Baseline and monitoring studies are actions implemented by the Gulf stakeholders to cope with such disturbances. The 3-year monitoring program implemented by Mexico in 2010 to assess the environmental damage caused by the Deepwater Horizon (DWH) event confirmed the void of knowledge on the complexity of physical and biological processes susceptible of being altered by oil spills. Between the pelagic and benthic compartments, the latter proved to be a better option in establishing the baseline concentration and trends of oil compounds. Surficial sediments exhibited an increasing concentration trend of PAH, AH, and trace metals throughout the 3-year monitoring. The macroinfauna and selected biomarkers experienced interannual variability attributed to critical hydrocarbon and trace metal thresholds. Sediment toxicity bioassays added support to the distribution and potential sources of oil contaminants dispersed from the northern gulf toward Mexican waters

Gestión del proyecto: “Reubicación de nido de ciclones de relaves fase II en Sociedad Minera Cerro Verde”

La actual presa de relaves comenzó su construcción en el 2004 e inicio actividades en 2006. A partir de entonces se ha desarrollado Ingeniería con principio de aprovechar la gravedad por la ubicación geográfica de la estación de cicloneo. Debido a la implementación del Debottlenecking Project que elevará la producción de la concentradora de una capacidad actual de 108,000 ton/día, a una capacidad requerida de 120,000 ton/día, para lo cual se cuenta con 02 estaciones de ciclones, la primera batería de ciclones CS01 que tiene un flujo máximo de ingreso de 5045 m3/h. y otra segunda batería de ciclones CS02 que tiene un flujo máximo de ingreso 5978 m3/h., la reubicación del sistema de ciclones en su nueva ubicación deberá considerar las modificaciones respectivas para procesar los flujos de relaves que resulten de este incremento en la producción. La actual presa de relaves comenzó su construcción en el 2004 e inició actividades en el 2006. A partir de entonces se ha desarrollado Ingeniería con principio de aprovechar la gravedad por la ubicación geográfica de la estaciones de cicloneo. El movimiento de ciclones debe ser cuidadosamente planificado de tal manera de disminuir al máximo el tiempo de parada considerado este en 5 semanas de parada del sistema y por tanto la pérdida de producción de arenas.The current tailings dam began construction in 2004 and began activities in 2006. Since then, Engineering has been developed with the principle of taking advantage of gravity due to the geographical location of the cyclone station. Due to the implementation of the Debottlenecking Project that will raise the concentrator's production from a current capacity of 108,000 tons / day, to a required capacity of 120,000 tons / day, for which there are 02 cyclone stations, the first battery of cyclones. CS01 which has a maximum inflow flow of 5045 m3 / h. and another second battery of cyclones CS02 that has a maximum inflow flow of 5978 m3 / h., the relocation of the cyclone system in its new location must consider the respective modifications to process the tailings flows that result from this increase in production. The current tailings dam began its construction in 2004 and began activities in 2006. Since then, Engineering has been developed with the principle of taking advantage of gravity due to the geographical location of the cyclone stations. The movement of cyclones must be carefully planned in such a way as to minimize the downtime considered in 5 weeks of system shutdown and therefore the loss of sand production.Tesi

Kinetics of Halophilic Enzymes

Hypersaline environments are those with salt concentrations 9–10 times higher (30–35% of NaCl) than sea water (3.5% of NaCl). At high concentrations of soluble salts, cytoplasm—mainly of bacteria and archaea—is exposed to high ionic strength and achieves osmotic equilibrium by maintaining a cytoplasmic salt concentration similar to that of the surrounding media. Halophilic enzymes are extremozymes produced by halophilic microorganisms; they have similar characteristics to regular enzymes but different properties, mainly structural. Among these properties is a high requirement of salt for biological functions. Furthermore, the discovery of enzymes capable of degrading biopolymers offer a new perspective in the treatment of residues from oil deposits, under typically high conditions of salt and temperature, while giving valuable information on heterotrophic processes in saline environments

Corrigendum: Variability of Bacterial Essential Genes Among Closely Related Bacteria: The Case of Escherichia coli

The definition of bacterial essential genes has been widely pursued using different approaches. Their study has impacted several fields of research such as synthetic biology, the construction of bacteria with minimal chromosomes, the search for new antibiotic targets, or the design of strains with biotechnological applications. Bacterial genomes are mosaics that only share a small subset of gene-sequences (core genome) even among members of the same species. It has been reported that the presence of essential genes is highly variable between closely related bacteria and even among members of the same species, due to the phenomenon known as “non-orthologous gene displacement” that refers to the coding for an essential function by genes with no sequence homology due to horizontal gene transfer (HGT). The existence of dormant forms among bacteria and the high incidence of HGT have been proposed to be driving forces of bacterial evolution, and they might have a role in the low level of conservation of essential genes among related bacteria by non-orthologous gene displacement, but this correlation has not been recognized. The aim of this mini-review is to give a brief overview of the approaches that have been taken to define and study essential genes, and the implications of non-orthologous gene displacement in bacterial evolution, focusing mainly in the case of Escherichia coli. To this end, we reviewed the available literature, and we searched for the presence of the essential genes defined by mutagenesis in the genomes of the 63 best-sequenced E. coli genomes that are available in NCBI database. We could not document specific cases of non-orthologous gene displacement among the E. coli strains analyzed, but we found that the quality of the genome-sequences in the database is not enough to make accurate predictions about the conservation of essential-genes among members of this bacterial species

ESTIMACIÓN DE LOS COEFICIENTES DE INERCIA Y DE FRICCIÓN DE UN MOTOR DE CD (ESTIMATION OF INERTIA AND FRICTION COEFFICIENTS OF A DC MOTOR)

ResumenEn este trabajo se presentan algunos modelos de fricción, y se destaca la importancia de los parámetros de fricción viscosa y de Coulomb, los cuales son necesarios para definir los distintos modelos que describen el comportamiento de la fricción en sistema mecánicos. Se describen los métodos de torque constante y entrada tipo rampa para estimar los coeficientes de fricción viscosa y de Coulomb, estos métodos se aplican en un motor de CD para obtener sus parámetros. A fin de comprobar que los parámetros estimados son los adecuados, se diseña y se aplica un control de velocidad, utilizando un controlador proporcional con compensación. La estimación de los parámetros y el control de velocidad del motor se realiza de forma experimental utilizando una plataforma de Arduino UNO en conjunto con la herramienta de Simulink de MatLab. Los resultados muestran que los coeficientes de fricción estimados son adecuados.Palabras Claves: control, estimación, fricción, motor de cd. AbstractIn this paper, some friction models are presented, highlighting the importance of viscous and Coulomb friction parameters, which are necessary to define the different models that describe the friction behavior in mechanical systems. The constant torque and ramp-type input methods for estimating viscous and Coulomb friction coefficients are described. These methods are applied in a DC motor, and their parameters are obtained. To verify that the estimated parameters are adequate, a speed control is designed and applied, using a proportional controller with compensation. Parameter estimation and motor speed control is performed experimentally using an Arduino UNO platform together with Simulink tool of MatLab. The results show that the estimated friction parameters are adequate.Keywords: control, friction, measurement, dc motor

Intrahippocampal infusion of crotamine isolated from Crotalus durissus terrificus alters plasma and brain biochemical parameters

CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPERGS - FUNDAÇÃO DE AMPARO A PESQUISA DO ESTADO DO RIO GRANDE DO SULCrotamine is one of the main constituents of the venom of the South American rattlesnake Crotalus durissus terrificus. Here we sought to investigate the inflammatory and toxicological effects induced by the intrahippocampal administration of crotamine isolated from Crotalus whole venom. Adult rats received an intrahippocampal infusion of crotamine or vehicle and were euthanized 24 h or 21 days after infusion. Plasma and brain tissue were collected for biochemical analysis. Complete blood count, creatinine, urea, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), creatine-kinase (CK), creatine kinase-muscle B (CK-MB) and oxidative parameters (assessed by DNA damage and micronucleus frequency in leukocytes, lipid peroxidation and protein carbonyls in plasma and brain) were quantified. Unpaired and paired t-tests were used for comparisons between saline and crotamine groups, and within groups (24 h vs. 21 days), respectively. After 24 h crotamine infusion promoted an increase of urea, GOT, GPT, CK, and platelets values (p ≤ 0.01), while red blood cells, hematocrit and leukocytes values decreased (p ≤ 0.01). Additionally, 21 days after infusion crotamine group showed increased creatinine, leukocytes, TBARS (plasma and brain), carbonyl (plasma and brain) and micronucleus compared to the saline-group (p ≤ 0.01). Our findings show that crotamine infusion alter hematological parameters and cardiac markers, as well as oxidative parameters, not only in the brain, but also in the blood, indicating a systemic pro-inflammatory and toxicological activity. A further scientific attempt in terms of preserving the beneficial activity over toxicity is required.Crotamine is one of the main constituents of the venom of the South American rattlesnake Crotalus durissus terrificus. Here we sought to investigate the inflammatory and toxicological effects induced by the intrahippocampal administration of crotamine isolated from Crotalus whole venom. Adult rats received an intrahippocampal infusion of crotamine or vehicle and were euthanized 24 h or 21 days after infusion. Plasma and brain tissue were collected for biochemical analysis. Complete blood count, creatinine, urea, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), creatine-kinase (CK), creatine kinase-muscle B (CK-MB) and oxidative parameters (assessed by DNA damage and micronucleus frequency in leukocytes, lipid peroxidation and protein carbonyls in plasma and brain) were quantified. Unpaired and paired t-tests were used for comparisons between saline and crotamine groups, and within groups (24 h vs. 21 days), respectively. After 24 h crotamine infusion promoted an increase of urea, GOT, GPT, CK, and platelets values (p ≤ 0.01), while red blood cells, hematocrit and leukocytes values decreased (p ≤ 0.01). Additionally, 21 days after infusion crotamine group showed increased creatinine, leukocytes, TBARS (plasma and brain), carbonyl (plasma and brain) and micronucleus compared to the saline-group (p ≤ 0.01). Our findings show that crotamine infusion alter hematological parameters and cardiac markers, as well as oxidative parameters, not only in the brain, but also in the blood, indicating a systemic pro-inflammatory and toxicological activity. A further scientific attempt in terms of preserving the beneficial activity over toxicity is required11111143811449CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPERGS - FUNDAÇÃO DE AMPARO A PESQUISA DO ESTADO DO RIO GRANDE DO SULCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPERGS - FUNDAÇÃO DE AMPARO A PESQUISA DO ESTADO DO RIO GRANDE DO SULsem informaçãosem informaçã

The optimal age for performing surgery on patients with MEN 2B syndrome

Multiple endocrine neoplasia (MEN) syndromes are characterized by the association of various endocrine neoplasias. Prophylactic thyroidectomy is the treatment of choice for patients with RET gene mutations. The age at which patients undergo prophylactic thyroidectomy may vary depending on the position of the RET gene codon. In cases of MEN 2B, when the mutation is carried in codons 883, 918 or 922, prophylactic thyroidectomy is performed prior to 6 months of age, due to the increased aggressiveness of these heterozygosities, which are capable of determining the onset of medullary cancer during the first months of life. We present two heterozygous twin patients with MEN 2B syndrome who were born 32 weeks premature, and who underwent prophylactic thyroidectomy at 7 months of age. The patients were carriers of the mutation at codon 918. We suggested the early surgery at 7 months as, due to their prematurity, the patients were required to gain weight to improve their condition prior to surgery. The two patients had medullary thyroid carcinoma without lymph node involvement. In conclusion, for a truly prophylactic thyroidectomy, such patients should undergo surgery within the first month of life, particularly if these patients are carriers of the mutation in codons 883, 918 or 922

The TGFBR1*6A allele is not associated with susceptibility to colorectal cancer in a Spanish population: a case-control study

Background: TGF-β receptor type I is a mediator of growth inhibitory signals. TGFBR1*6A (rs11466445) is a common polymorphic variant of the TGF-β receptor I gene and has been associated with tumour susceptibility. Nevertheless, the role of this polymorphism as a risk factor for colorectal cancer is controversial. The aim of this study was to assess the association between TGFBR1*6A and colorectal cancer, age, sex, tumour location and tumour stage in a Spanish population. Methods: The case-control study involved 800 Spanish subjects: 400 sporadic colorectal cancer patients and 400 age-, sex-, and ethnic-matched controls. The odds ratio (OR) and 95% confidence interval (95% CI) for the TGFBR1*6A polymorphism were calculated using unconditional logistic regression adjusted for age and sex. Analysis of somatic mutations at the GCG repeat of TGFBR1 exon 1 and germline allele-specific expression were also conducted to obtain further information on the contribution of the TGFBR1*6A allele to CRC susceptibility. Results: There was no statistically significant association between the TGFBR1*6A allele and CRC (p > 0.05). The OR was 1.147 (95% CI: 0.799–1.647) for carriers of the TGFBR1*6A allele and 0.878 (95% CI: 0.306–2.520) for homozygous TGFBR1*6A individuals compared with the reference. The frequency of the polymorphism was not affected by age, sex or tumour stage. The TGFBR1*6A allele was more prevalent among colon tumour patients than among rectal tumour patients. Tumour somatic mutations were found in only two of 69 cases (2.9%). Both cases involved a GCG deletion that changed genotype 9A/9A in normal DNA to genotype 9A/8A. Interestingly, these two tumours were positive for microsatellite instability, suggesting that these mutations originated because of a deficient DNA mismatch repair system. Allele-specific expression of the 9A allele was detected in seven of the 14 heterozygous 9A/6A tumour cases. This could have been caused by linkage disequilibrium of the TGFBR1*6A allele with mutations that cause allele-specific expression, as was recently suggested. Conclusion: Our results suggest that the TGFBR1*6A allele does not confer an increased risk of colorectal cancer in the Spanish population.The research was supported in part by grants from the Generalitat Valenciana in Spain (AP106/06) and the Biomedical Research Foundation of the Hospital of Elche (FIBElx-02/2007). T.M-B was a recipient of a fellowship from the Spanish Society of Medical Oncology