19 research outputs found

    Estimation of anthropogenic organo-chlorine, bromine and iodine compounds in apolar lipid fractions of bovine milk by solid-phase extraction and neutron activation analysis (SPE–NAA)

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    Articulo cientifico publicado en: Journal of Radioanalytical and Nuclear Chemistry (2018) 318:247–257 https://doi.org/10.1007/s10967-018-6086-8Milk lipids were separated using a hexane:isopropanol mixture; then they were fractionated into apolar, medium polar and polar portions by SPE using a LC-Si column. The apolar fraction was further separated into 4 more portions depending on their polarity by another SPE method using a Florosil column. Levels of Cl, Br and I were measured by NAA. Halogens were detected in all separated fractions; but their highest levels were found in the most apolar fraction containing hydrocarbons which strongly indicates the presence of anthropogenic organohalogen compounds in milk. In addition, iodide and iodate ions in whole milk samples were measured

    Búsqueda de capacidad productora de biosurfactantes en actinobacterias haloalcalófilas y haloalcalotolerantes

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    Una opción para biorremediar ambientes salinos contaminados con compuestos orgánicos hidrofóbicos, es el uso de microorganismos haloalcalófilos o haloalcalotolerantes capaces de producir biosurfactantes estables y consumir al compuesto hidrófobo. El biosurfactante solubiliza al contaminante haciéndolo biodisponible para el microrganismo. De estudios previos se conocía la capacidad de siete actinobacterias haloalcalotolerantes para transformar el antraceno. En este trabajo, a estas siete más 11 más aisladas de ambientes salinos, se les determinó la capacidad para producir biosurfactantes con propiedades emulsificantes. A las que la mostraron, fueron seleccionadas para saber si utilizaban al antraceno como única fuente de carbono y energía. La capacidad para producir biosurfactante fue determinada por los métodos de actividad hemolítica, gota colapsada y difusión del diámetro de la gota. La propiedad emulsificante y la estabilidad de la emulsión se caracterizaron con el índice de emulsificación y el índice de emulsificación relativo, respectivamente. De 18 actinobacterias evaluadas, cinco cepas mostraron capacidad para producir biosurfactantes con propiedades emulsificantes, alta estabilidad en la emulsión y utilización de antraceno como única fuente de carbono y energía. De estas cinco, dos son haloalcalófilas pertenecientes a la especie Nocardiopsis salina y tres son haloalcalotolerantes pertenecientes a las especies: Kocuria palustris, Microbacterium testaceum y Kocuria rosea. En un estudio previo se determinó la capacidad transformadora de antraceno en las tres cepas haloalcalotolerantes, por lo tanto los resultados de este estudio sugieren proponerlas como candidatas para procesos de biorremediación de ambientes salinos contaminados con compuestos hidrófobos. Asimismo se sugiere determinar la misma capacidad para las dos cepas haloalcalófilas.SIEA-UAEMex 3690/2014/CID SIEA-UAEMex 1039/2014RIFC SEP-PRODEP-Convocatoria de Redes 201

    Study of the Optical Properties of Functionalized Gold Nanoparticles in Different Tissues and Their Correlation with the Temperature Increase

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    Mie theory explains the interaction of light with a gold nanoparticle (AuNP) through the absorption (abs), scattering (sca), and extinction (ext) cross sections. These parameters have been calculated in the case of AuNPs dispersed in homogeneous media, but not for specific tissues. The aim of this research was to theoretically obtain the optical cross sections (abs, sca, and ext) of functionalized AuNPs in liver and colon tissues through Mie theory and correlate them with the temperature increase observed experimentally in tissues containing AuNPs under plasmonic photothermal irradiation using a Nd-YAG laser ( = 532 nm). Calculations showed that abs represents 98.96 ± 0.03% of ext at 532 nm. The ext value for a functionalized AuNP in water was 365.66 nm2 (94% of the theoretical maximum value at 522.5 nm), 404.24 nm2 in colon (98% of the theoretical maximum value at 525 nm), and 442.39nm2 in liver (96% of the theoretical maximum value at 525 nm). Therefore, nanoparticles irradiated at 532nm are very close to their resonance value.These results correlated with the experimental irradiation of functionalized AuNPs in different tissues, where the average temperature increase showed the pattern liver > colon > water. The temperature increase observed (Δ up to 13∘C) is sufficient to produce cellular death.CATEDRAS-CONACYT-ININ-337 CONACYT-SEP-CB-2014-01-242443)

    Preliminary clinical experience of the systemic use of 153Sm-EDTMP as a pain palliation agent in arthrosis and as an option for bone scanning in patients with bone metastases

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    Introducción: Muchos pacientes con artrosis tienen efectos secundarios producidos por los tratamientos convencionales. Estos pacientes son candidatos para tratamiento paliativo del dolor con 153Sm-EDTMP. Los pacientes con metástasis ósea, por lo general, requieren un rastreo utilizando ‘Tc-MDP, antes del tratamiento paliativo con 3Sm-EDTMP. Este trabajo tiene 2 objetivos: 1) evaluar el uso de 153Sm-EDTMP como alternativa en Los procedimientos de rastreo óseo en pacientes con metástasis ósea y, 2) si el 153Sm-EDTMP es captado en la articulación lesionada con artrosis, entonces se evalúa el uso eficiente y seguro de la administración sistémica de este radiofármaco, para Ia paliación del dolor por artrosis. Métodos y materiales: Una muestra no probabilística, de oportunidad y secuencial de 10 pacientes con artrosis fue seleccionada, así como, un paciente con metástasis ósea secundaria a cáncer de próstata. En Los 11 pacientes se realizaron gammagrafias óseas con Los radiofármacos “Tc-MDP y ls3mEDTMP, para comparar [a calidad de imagen y sitios de captación. En los pacientes con artrosis se administró por vía sistémica una dosis terapéutica de ‘Sm-EDTMP para la paliación del dolor. Se realizaron perfiles hematológicos con el fin de garantizar La seguridad de la médula ósea. La evolución del dolor y de la motilidad se utilizó para evaluar La eficacia analgésica 3Sm-EDTMR Resultados y conclusión: La calidad de imagen obtenida en Los 11 pacientes con ‘3Snì-EDTMP es similar desde el punto de vista clínico, a Ias obtenidas con ‘“Tc-MDR EL 3Sm-EDTMP es captado por las articulaciones con artrosis y metástasis óseas. La dosis terapéutica de 1’Sm-EDTMP administrada por vía intravenosa fue bien tolerada por Ia médula ósea en todos Los pacientes, así como hubo un efecto analgésico, por lo que mejoró la motilidad y la calidad de vida en los pacientes con artrosis.Introduction: Many patients with arthrosis have side effects produced by conventional treatments. These patients are candidates for pain palliation with 153Sm-EDTMP. Patients with cancer bone metastases usuaLly require a bone scanning procedure using ““Tc-MDP, prior to treatment through 153Sm-EDTMP. This work has two aims. Firstly, to assess the use of 153Sm- EDTMP as an alternative in bone scanning procedures in patients with bones metastases. Se condly, if the 153Sm-EDTMP is uptaken by the arthrosis injured joint, then the efficient and safe use of the systemic administration of this radiopharmaceutical is evaluated for pain palliation. Methods and materials: A non-probabilistic, of opportunity and sequential sample of 10 patients with arthrosis was selected, as well as, one patient with bone metastasis secondary to prostate cancer. In the li patients, bone scans were performed using both radiopharmaceuticals “‘T1Tc- MDP and 153Sm-EDTMP to compare image quality and uptake sites. In patients with arthrosis a therapeutic dose with ‘53Sm-EDTMP was systemically administered for pain palliation. Hemato logic profiles were performed in order to assure security to the bone marrow. Pain and motility evaluations were carried out to assess the Sm-EDTMP analgesic efficacy. Results and conclusion: The Image qualities obtained with 13Sm-EDTMP are similar from the cLinical point of view to those obtained with ““Tc-MDR Sm-EDTMP is captured by joints with arthrosis and bone metastases. Therapeutic doses of 1Sm-EDTMP intravenously administered are well tolerated by the bone marrow, while an analgesic effect is present which improves motility and quality of Life in patients with arthrosis

    Theoretical and experimental characterization of emission and transmission spectra of Cerenkov radiation generated by 177Lu in tissue

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    Cerenkov radiation (CR) is the emission of UV-vis light generated by the de-excitation of the molecules in the medium, after being polarized by an excited particle traveling faster than the speed of light. When β particles travel through tissue with energies greater than 219 keV, CR occurs. Tissues possess a spectral optical window of 600 to 1100 nm. The CR within this range can be useful for quantitative preclinical studies using optical imaging and for the in-vivo evaluation of 177Lu-radiopharmaceuticals (β-particle emitters). The objective of our research was to determine the experimental emission light spectrum of 177Lu-CR and evaluate its transmission properties in tissue as well as the feasibility to applying CR imaging in the preclinical studies of 177Lu-radiopharmaceuticals. The theoretical and experimental characterizations of the emission and transmission spectra of 177Lu-CR in tissue, in the vis-NIR region (350 to 900 nm), were performed using Monte Carlo simulation and UV-vis spectroscopy. Mice 177Lu-CR images were acquired using a charge-coupled detector camera and were quantitatively analyzed. The results demonstrated good agreement between the theoretical and the experimental 177Lu-CR emission spectra. Preclinical CR imaging demonstrated that the biokinetics of 177Lu-radiopharmaceuticals in the main organs of mice can be acquiredThis study was supported by the Mexican National Council of Science and Technology (CONACYT) through the CATEDRAS-CONACYT-ININ-337 and CONACYT-SEP-CB- 2016-286753 projects. It was carried out as part of the activities of the “Laboratorio Nacional de Investigación y Desarrollo de Radiofármacos, CONACyT (LANIDER-CONACYT)” and the Red-Biofotónica, CONACYT. The financial support of the SIEA-UAEMex through the Grant No 4348/2017/CI is also acknowledged

    Molecular Identification of Mycobacterium Species of Public Health and Veterinary Importance from Cattle in the South State of México

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    Mycobacterium genus causes a variety of zoonotic diseases. The best known example is the zoonotic tuberculosis due to M. bovis. Much less is known about “nontuberculous mycobacteria (NTM),” which are also associated with infections in humans. The Mexican standard NOM-ZOO-031-1995 regulates the presence of M. bovis in cattle; however, no regulation exists for the NTM species. The objective of this study was to isolate and identify nontuberculous mycobacteria species from cattle of local herds in the south region of the State of Mexico through the identification and detection of the 100 bp molecular marker in the 23S rRNA gene with subsequent sequencing of the 16S rRNA gene.Milk samples (35) and nasal exudate samples (68) were collected. From the 108 strains isolated, 39 were selected for identification. Thirteen strains isolated from nasal exudates amplified the 100 bp molecular marker and were identified as M. neoaurum (six strains), M. parafortuitum (four strains), M. moriokaense (two strains), and M. confluentis (one strain). Except M. parafortuitum, the other species identified are of public health and veterinary concern because they are pathogenic to humans, especially those with underlying medical conditions

    Haloalkalitolerant Actinobacteria with capacity for anthracene degradation isolated from soils close to areas with oil activity in the State of Veracruz, Mexico

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    The use of native strains of microorganisms from soils is an excellent option for bioremediation. To our knowledge, until now there has been no other group working on the isolation of Actinobacteria from contaminated soils in Mexico. In this study, samples of soils close to areas with oil activity in the State of Veracruz, Mexico, were inoculated for the isolation of Actinobacteria. The strains isolated were characterized morphologically, and the concentrations of NaCl and pH were determined for optimal growth. Strain selection was performed by the detection of a phylogenetic marker for Actinobacteria located at the 23S rRNA gene, followed by species identification by sequencing the 16S rRNA gene. Several haloalkalitolerant Actinobacteria were isolated and identified as: Kocuria rosea, K. palustris, Microbacterium testaceum, Nocardia farcinica and Cellulomonas denverensis. Except for C. denverensis, the biomass of all strains increased in the presence of anthracene. The strains capacity to metabolize anthracene (at 48 h), determined by fluorescence emission, was in the range of 46–54%. During this time, dihydroxy aromatic compounds formed, characterized by attenuated total reflectance Fourier transform infrared spectroscopy bands of 1205 cm–1 and 1217 cm–1. Those Actinobacteria are potentially useful for the bioremediation of saline and alkaline environments contaminated with polycyclic aromatic hydrocarbon compounds

    Determination of the Residual Anthracene Concentration in Cultures of Haloalkalitolerant Actinomycetes by Excitation Fluorescence, Emission Fluorescence, and Synchronous Fluorescence: Comparative Study

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    Polycyclic aromatic hydrocarbons (PAHs) are compounds that can be quantified by fluorescence due to their high quantum yield. Haloalkalitolerant bacteria tolerate wide concentration ranges of NaCl and pH. They are potentially useful in the PAHs bioremediation of saline environments. However, it is known that salinity of the sample affects fluorescence signal regardless of the method.The objective of this work was to carry out a comparative study based on the sensitivity, linearity, and detection limits of the excitation, emission, and synchronous fluorescence methods, during the quantification of the residual anthracene concentration from the following haloalkalitolerant actinomycetes cultures Kocuria rosea, Kocuria palustris, Microbacterium testaceum, and 4 strains of Nocardia farcinica, in order to establish the proper fluorescence method to study the PAHs biodegrading capacity of haloalkalitolerant actinobacteria. The study demonstrated statistical differences among the strains and among the fluorescence methods regarding the anthracene residual concentration. The results showed that excitation and emission fluorescence methods performed very similarly but sensitivity in excitation fluorescence is slightly higher. Synchronous fluorescence using Δ = 150nm is not the most convenient method.Therefore we propose the excitation fluorescence as the fluorescence method to be used in the study of the PAHs biodegrading capacity of haloalkalitolerant actinomycetes

    ESTUDIO EXPLORATORIO SOBRE LA ASOCIACIÓN DE METALES PESADOS Y LA NEFROPATÍA DE ETIOLOGÍA DESCONOCIDA EN EL PONIENTE DEL ESTADO DE MÉXICO

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    Artículo publicado en: Rev. Int. Contam. Ambie. 34 (4) 555-564, 2018 DOI: 10.20937/RICA.2018.34.04.01En el occidente del Estado de México, la mitad de los ingresos hospitalarios por insuficiencia renal crónica (IRC) no asociada a diabetes mellitus ni a hipertensión arterial corresponden a personas menores de 40 años. Por lo tanto, esta IRC se considera de causas desconocidas (IRCd). En este trabajo se estudió la asociación entre la presencia de metales y factores de riesgo para IRCd. Se realizó un estudio transversal analítico de 100 casos y 100 testigos. Se aplicó un cuestionario para conocer las adicciones y exposiciones (alimentarias, ocupacionales y medicamentosas) de los sujetos. En 50 casos y 50 testigos se determinó la concentración de los metales arsénico, cadmio, mercurio y plomo en muestras de cabello. Finalmente, se construyó un mapa con la posición de la vivienda de los 100 pacientes. Con base en una regresión logística bivariada se determinó que existe una asociación estadísticamente significativa entre la IRCd y el consumo de tabaco, exposición ocupacional a la construcción y herrería, y exposición a arsénico. Es necesaria una muestra mayor para comprobar la exposición ocupacional a la industria del papel, al consumo de paracetamol, naproxeno y cadmio. Los valores obtenidos en este trabajo para estas variables mencionadas son sólo informativos. Los casos estudiados se localizan en la cuenca del Rio Lerma, uno de los más contaminados del país. La IRCd presente en el Estado de México parece ser muy similar a la de Siri Lanka y la del Pacífico centroamericano, por lo que se requieren estudios a mayor escala.Fondo de Fomento y Desarrollo de la Investigación Científica y Tecnológica de la Universidad Autónoma del Estado de México, proyecto con clave 3896/2015E

    Engineered rHDL Nanoparticles as a Suitable Platform for Theranostic Applications

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    Reconstituted high-density lipoproteins (rHDLs) can transport and specifically release drugs and imaging agents, mediated by the Scavenger Receptor Type B1 (SR-B1) present in a wide variety of tumor cells, providing convenient platforms for developing theranostic systems. Usually, phospholipids or Apo-A1 lipoproteins on the particle surfaces are the motifs used to conjugate molecules for the multifunctional purposes of the rHDL nanoparticles. Cholesterol has been less addressed as a region to bind molecules or functional groups to the rHDL surface. To maximize the efficacy and improve the radiolabeling of rHDL theranostic systems, we synthesized compounds with bifunctional agents covalently linked to cholesterol. This strategy means that the radionuclide was bound to the surface, while the therapeutic agent was encapsulated in the lipophilic core. In this research, HYNIC-S-(CH2)3-S-Cholesterol and DOTA-benzene-p-SC-NH-(CH2)2-NH-Cholesterol derivatives were synthesized to prepare nanoparticles (NPs) of HYNIC-rHDL and DOTA-rHDL, which can subsequently be linked to radionuclides for SPECT/PET imaging or targeted radiotherapy. HYNIC is used to complexing 99mTc and DOTA for labeling molecules with 111, 113mIn, 67, 68Ga, 177Lu, 161Tb, 225Ac, and 64Cu, among others. In vitro studies showed that the NPs of HYNIC-rHDL and DOTA-rHDL maintain specific recognition by SR-B1 and the ability to internalize and release, in the cytosol of cancer cells, the molecules carried in their core. The biodistribution in mice showed a similar behavior between rHDL (without surface modification) and HYNIC-rHDL, while DOTArHDL exhibited a different biodistribution pattern due to the significant reduction in the lipophilicity of the modified cholesterol molecule. Both systems demonstrated characteristics for the development of suitable theranostic platforms for personalized cancer treatment.Consejo Nacional de Ciencia y Tecnología (CONACyT, Mexico), through Grant SEP-CONACyT-CB-2016-01-287217. the financing program for female scientists EDOMEX, Grant Number FICDTEM-2021-015
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