CUERPO ACADÉMICO DE FÍSICA MÉDICA (CONSOLIDADO)

La radioterapia estereotáctica del cuerpo involucra la entrega de alta dosis absorbida en pocas fracciones por lo que es necesaria una inmovilización controla y supervisada del paciente y del volumen del blanco en un espacio de tres dimensiones. El propósito de este trabajo fue analizar el desempeño del sistema de imagen para corrección y verificación de la posición del isocentro ExacTrac (ETX) en el American British Cowdray Medical Center en la Ciudad de Méxic

POS-COVID-19 EN JÓVENES UNIVERSITARIOS

Abstract Introduction: Post-covid 19 syndrome became widespread dueto the large amount of general malaise that patients infected with the SARS-CoV-2 virus have manifested, identifying some of them as delicate in terms of health. Objective: To identify the main post-covid-19 conditions that occur in young university students. Material and Methods: An observational, descriptive, cross-sectional, descriptive study was carried out with students of the bachelor’s degrees of Medical Surgeon and Nutrition of the Faculty of Medicine of the uaemex in the 2023. Results: The most common symptoms during illness were cough, palpitations and chest tightness and headache, cardiovascular problems and fatigue. Some students manifested olfactory alterations. In sever- al patients the health problems persisted even after the disease had disappeared. 32.7% reported deep fatigue despite rest, 30.6% unrefreshing sleep and 26.5% cognitive impairment as the main sequelae. Some people also present intolerance to standing and discomfort or worsening after physical exertion. Conclusions: The SARS-CoV-2 virus in many cases leaves important sequelae, so it is essential to have accurate and timely information that allows us to care for patients. We must wait until the end of the adolescence stage of those who suffered from covid-19 to be certain of the possible long-term sequelae.Resumen Introducción: El síndrome pos-covid-19 se difundió por la gran cantidad de malestar general que han manifestado los pacientes contagiados con el virus SARS-CoV-2, reconociendo algunas de ellas como delicadas en términos de salud. Objetivo: Identificar las principales afecciones pos-covid-19 que se presentan en jóvenes universitarios. Material y Métodos: Se realizó un estudio observacional,descriptivo, transversal, con los alumnos de las licenciaturas de Médico Cirujano y Nutrición de la Facultad de Medicina de la uaemex en el 2023. Resultados: Los síntomas más comunes durante la enfermedad fueron tos, palpitaciones y opresión en el pecho y dolor de cabeza, problemas cardiovasculares y fatiga. Algunos alumnos manifestaron alteraciones olfativas. En varios pacientes los problemas de salud persistieron aún después de desaparecer la enfermedad. El 32.7% manifiestan fatiga profunda a pesar del descanso, 30.6% sueño no reparador y 26.5% afectación cognitiva, como las principales secuelas. Algunas personas también presentan intolerancia a permanecer de pie y malestar o empeoramiento tras el esfuerzo físico. Conclusiones: El virus SARS-CoV-2 en muchos casos deja secuelas importantes, por lo que es indispensable disponer de información precisa y oportuna que permita atender a los pacientes. Debemos esperar a que concluya la etapa de adolescencia de quienes en su momento padecieron covid-19, para tener a ciencia cierta la certeza de las posibles secuelas a largo plazo

POS-COVID-19 EN JÓVENES UNIVERSITARIOS

Introducción: El síndrome pos-COVID-19 se difundió por la gran cantidad de malestar general que han manifestado los pacientes contagiados con el virus SARS-CoV-2, reconociendo algunas de ellas como delicadas en términos de salud.   Objetivo: Identificar las principales afecciones pos-COVID-19 que se presentan en jóvenes universitarios. Material y Métodos: Se realizó un estudio observacional, descriptivo, transversal, con los alumnos de las licenciaturas de médico cirujano y nutrición de la Facultad de Medicina de la UAEMex en el año 2023. Resultados: Los síntomas más comunes durante la enfermedad fueron tos, palpitaciones y opresión en el pecho y dolor de cabeza, problemas cardiovasculares y fatiga. Algunos alumnos manifestaron alteraciones olfativas. En varios pacientes los problemas de salud persistieron aún después de desaparecer la enfermedad. El 32.7% manifiestan fatiga profunda a pesar del descanso, 30.6% sueño no reparador y 26.5% afectación cognitiva, como las principales secuelas. Algunas personas también presentan intolerancia a permanecer de pie y malestar o empeoramiento tras el esfuerzo físico. Conclusiones: El virus SARS-CoV-2 en muchos casos deja secuelas importantes, por lo que es indispensable disponer de información precisa y oportuna que permita atender a los pacientes. Debemos esperar a que concluya la etapa de adolescencia de quienes en su momento padecieron la COVID-19, para tener a ciencia cierta la certeza de las posibles secuelas a largo plazo

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

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. [Int Microbiol 2016; 19(1):15-26]Keywords: Kocuria · Microbacterium · haloalkalitolerant Actinobacteria · anthracene degradation · State of Veracruz, Mexic

Preparation and in vitro evaluation of 177Lu-iPSMA-RGD as a new heterobivalent radiopharmaceutical

This study aimed to synthesize a new 177Lu-iPSMA-RGD heterobivalent radiopharmaceutical, as well as to assess the in vitro radiopharmaceutical potential to target cancer cells overexpressing PSMA and a(v) b(3) integrins. The radiotracer prepared with a radiochemical purity of 98.8 ± 1.0% showed stability in human serum, specific recognition with suitable affinity to PSMA and a(v)b(3) integrins, and capability to inhibit cancer cell proliferation and VEGF signaling (antiangiogenic effect). Results warrant further preclinical studies to establish the 177Lu-iPSMA-RGD potential as a dual therapeutic radiopharmaceutical.CONACyT-CB-2016-01-28152

Microorganisms and spatial distribution of the sinkholes of the Yucatan Peninsula, underestimated biotechnological potential?

Investigación basada en el potencial bio-tecnológico de las micro-especies que habitan los cenotes de la Península de YucatánAbstract Objective: To detect the spatial distribution of the sinkholes of the Peninsula of Yucatan (SPY) and identify those cenotes where microorganisms have been registered. Methods: The geographic coordinates of the SPYs were obtained from various databases, as well as from scientific publications relating to the terminology ‘sinkholes’, ‘karst systems’ and ‘cenotes’. All coordinates were transformed into the Universal Transverse Mercator reference system (UTM) with datum WGS84. An infrared composite image was created with 432 RGB bands from the Landsat 8 satellite. The points with the location of the cenotes were imported into the Software TerrSet. Results: Total 1026 coordinates of sinkholes were recorded in the Yucatan Peninsula. In 18 sinkholes (<2%), microorganisms have been recovered and identified in various taxonomic levels, and only 6 sinkholes (<0.6%) has their biotechnological potential been evaluated. Conclusions: The microorganisms that inhabit the sinkholes of the Yucatan Peninsula are a reservoir with practically unexplored biotechnological potential.CONACY

Development and validation of a diagnostic aid for convulsive epilepsy in sub-Saharan Africa: a retrospective case-control study

Background: Identification of convulsive epilepsy in sub-Saharan Africa relies on access to resources that are often unavailable. Infrastructure and resource requirements can further complicate case verification. Using machine-learning techniques, we have developed and tested a region-specific questionnaire panel and predictive model to identify people who have had a convulsive seizure. These findings have been implemented into a free app for health-care workers in Kenya, Uganda, Ghana, Tanzania, and South Africa. Methods: In this retrospective case-control study, we used data from the Studies of the Epidemiology of Epilepsy in Demographic Sites in Kenya, Uganda, Ghana, Tanzania, and South Africa. We randomly split these individuals using a 7:3 ratio into a training dataset and a validation dataset. We used information gain and correlation-based feature selection to identify eight binary features to predict convulsive seizures. We then assessed several machine-learning algorithms to create a multivariate prediction model. We validated the best-performing model with the internal dataset and a prospectively collected external-validation dataset. We additionally evaluated a leave-one-site-out model (LOSO), in which the model was trained on data from all sites except one that, in turn, formed the validation dataset. We used these features to develop a questionnaire-based predictive panel that we implemented into a multilingual app (the Epilepsy Diagnostic Companion) for health-care workers in each geographical region. Findings: We analysed epilepsy-specific data from 4097 people, of whom 1985 (48·5%) had convulsive epilepsy, and 2112 were controls. From 170 clinical variables, we initially identified 20 candidate predictor features. Eight features were removed, six because of negligible information gain and two following review by a panel of qualified neurologists. Correlation-based feature selection identified eight variables that demonstrated predictive value; all were associated with an increased risk of an epileptic convulsion except one. The logistic regression, support vector, and naive Bayes models performed similarly, outperforming the decision-tree model. We chose the logistic regression model for its interpretability and implementability. The area under the receiver operator curve (AUC) was 0·92 (95% CI 0·91–0·94, sensitivity 85·0%, specificity 93·7%) in the internal-validation dataset and 0·95 (0·92–0·98, sensitivity 97·5%, specificity 82·4%) in the external-validation dataset. Similar results were observed for the LOSO model (AUC 0·94, 0·93–0·96, sensitivity 88·2%, specificity 95·3%). Interpretation: On the basis of these findings, we developed the Epilepsy Diagnostic Companion as a predictive model and app offering a validated culture-specific and region-specific solution to confirm the diagnosis of a convulsive epileptic seizure in people with suspected epilepsy. The questionnaire panel is simple and accessible for health-care workers without specialist knowledge to administer. This tool can be iteratively updated and could lead to earlier, more accurate diagnosis of seizures and improve care for people with epilepsy

Radiofármaco teragnóstico basado en dendrímeros conjugados a ácido fólico y Lys3 -bombesina con nanopartículas de oro en la cavidad dendrítica

Theragnostics (or theranostics) is an acronym of therapeutics and diagnostics. In this project, theterm refers to molecular/macromolecular vectors of specific recognition and nanoplatforms thatincorporate both functions, diagnosisand therapy simultaneously. In addition, the incorporation ofdiagnostic and therapeutics functions may be useful in monitoring disease progress and evaluatingthe response to combined therapy.By using radiopharmaceuticals, it is possible to record and detect by in vivo imaging thespatio-temporal distribution of molecular or cellular processes for diagnostic and therapeuticapplications using nuclear medicine techniques. Lutetium-177-based radiopharmaceuticals areconsidered theranostic systems because of their gamma emission (208 keV ) useful for performingthe diagnostic image and its negative beta radiation(Emax0.498 M eV ) suitable for therapeuticapplications. In this thesis it is reported for the first time, the preparation of a new multivalent andmultifunctional lutetium-177 radiopharmaceutical based on a dendrimer (PAMAM-G4) containinggold nanoparticles, folic acid, and the peptide bombes insuitable for targeted radiotherapy,plasmonic-photothermal therapy and dual molecular imaging (optic and nuclear) of breast cancer.Therefore, the first aim of this research was to synthesize177Lu-dendrimer-folate-bombesin with gold nanoparticles (AuNPs) in the dendritic cavity (177Lu-DenAuNP-Folate-Bombesin)and to evaluate the radiopharmaceutical potential for targeted radiotherapy and thesimultaneous detection of folate receptors (FRs) and gastrin-releasing peptide receptors (GRPRs)over-expressed in breast cancer cells. p-SCN-Benzyl-DOTA was linked to the dendrimer in anaqueous-basic medium. The carboxylate groups of Lys1Lys3(DOTA)-Bombesin and folic acid wereactivated with HATU and conjugated to the dendrimer.The conjugate was mixed with 1 % HAuCl4followed by the addition of NaBH4and purified byultrafiltration. Elemental analysis (EDS), particle size distribution (DLS), TEM analysis, UV-Vis,infrared and fluorescence spectroscopies were performed. The conjugate was radiolabeled using177LuCl3and analyzed by radio-HPLC. Studies confirmed the dendrimer functionalization withhigh radiochemical purity (> 95 %). Fluorescence results demonstrated that the presence of AuNPsin the dendritic cavity confers useful photophysical properties to the radiopharmaceutical for opticalimaging. Binding studies in T47D breast cancer cells showed a specific cell uptake (41.15 ± 2.72 %).177Lu-Dendrimer(AuNP)-Folate-Bombesin showed suitable properties as an optical and nuclearimaging agent for breast tumors over-expressing GRPR and FRs, as well as for target-specifictherapy. The integration of fluorescence and plasmonic properties into one molecule is of importancein developing multifunctional imaging and therapy nanoprobes.The second aim of this research was to evaluate the fluorescent properties and the plasmonic-photothermal therapeutic and radiotherapeutic potential of177Lu-DenAuNP-Folate-Bombesinwhen it is internalized in T47D breast cancer cells. The intense NIR fluorescence emitted fromthe conjugate inside cells corroborated the usefulness of DenAuNP-Folate-Bombesin for opticalimaging. After laser irradiation, the presence of the nanosystem in cells caused a significant increasein the temperature of the medium resulting in a significant decrease in cell viability (down to 16.51± 1.52 %)due to the177Lu-DenAuNP-Folate-Bombesin plasmonic properties. After treatment with177Lu-DenAuNP-Folate-Bombesin, the T47D cell viability decreased 90 % because of the radiation absorbed dose (63.16 ± 4.20 Gy) delivered inside cells. In conclusion, the177Lu-DenAuNP-Folate-Bombesin nanosystem internalized in cancer cells exhibited properties suitable for optical imaging,plasmonic-photothermal therapy, and targeted radiotherapy.Teragnósticos (o teranósticos) es un acrónimo de terapéuticos y diagnósticos. En este proyecto, el término se refiere a vectores moleculares/macromoleculares de reconocimiento específico y a nanoplataformas que incorporan ambas funciones, diagnóstico y terapia de forma simultánea. Además de incorporar funciones diagnósticas y terapéuticas, estas entidades pueden ser útiles en el seguimiento de la progresión de la enfermedad y en la evaluación de la respuesta a la terapia combinada. Por otro lado, a través del uso de radiofármacos es posible registrar y detectar por imagen in vivo, la distribución espacio-temporal de procesos moleculares o celulares para aplicaciones diagnósticas y/o terapéuticas utilizando técnicas de medicina nuclear molecular. En particular, los radiofármacos basados en lutecio-177 son considerados teranósticos por su emisión gamma (208 keV ), útil para realizar la imagen diagnóstica, y por su emisión beta negativa (Emax 498 keV ) adecuada para aplicaciones terapéuticas. En este trabajo de tesis se reporta por primera vez, la preparación de un nuevo radiofármaco de lutecio-177 multivalente y multifuncional basado en un dendrímero (PAMAM-G4) conteniendo nanopartículas de oro en sus cavidades y conjugado a ácido fólico y al péptido bombesina, para su posible uso en radioterapia dirigida, terapia fototérmica plasmónica e imagen molecular dual (óptica y nuclear) de cáncer de mama. Por tanto, el primer objetivo de esta investigación fue sintetizar 177Lu-dendrímero-folato-bombesina con nanopartículas de oro (AuNPs) en la cavidad dendítica (177Lu-DenAuNPFolato-Bombesina) y evaluar el potencial del radiofármaco para la radioterapia dirigida y la detección simultánea de receptores de folato (FR) y de receptores del péptido liberador de gastrina (GRPRs) sobre-expresados en células de cáncer de mama. El p-SCN-bencil-DOTA se conjugó en medio acuoso básico a los grupos amino del dendrímero. Los grupos carboxilato de la Lys1-Lys3 (DOTA)-bombesina y el ácido fólico se activaron con HATU y también se conjugaron al dendrímero. El conjugado se mezcló con HAuCl4 seguido de la adición de NaBH4 y se purific´ mediante ultrafiltraci´on. Se realiz´o el an´alisis elemental (EDS), la distribuci´on de tamañó de partícula (DLS), análisis de TEM, espectroscopia de UV-Vis, infrarrojo y de fluorescencia. El conjugado se marcó radiactivamente usando 177LuCl3 y se analizó por radio-HPLC. Los estudios confirmaron la funcionalización del dendrímero con alta pureza radioquímica (> 95 %). Los resultados de fluorescencia demostraron que la presencia de AuNPs en las cavidades dendríticas confiere al radiofármaco propiedades físicas útiles para la obtención de imágenes ópticas. Los estudios de unión en células de cáncer de mama T47D mostraron una captación celular específica (41,15 ± 2,72 %). Por tanto, el 177Lu-DenAuNP-Folato-Bombesina presenta propiedades adecuadas como un agente de imagen óptica y nuclear para tumores de mama que sobre-expresan GRPR y FRs, así como un nanosistema con potencial para ser utilizado en radioterapia de blancos moleculares específicos. La integración de propiedades fluorescentes y plasmónicas en una molécula es de importancia en el desarrollo de nanosensores multifuncionales para imagen y terapia. El segundo objetivo de esta investigación fue evaluar las propiedades fluorescentes y el potencial terapéutico fototérmico plasmónico y radioterapéutico del 177Lu-DenAuNP-Folato-Bombesina cuando se internaliza en células T47D de cáncer de mama. La fluorescencia intensa NIR emitida a 825 nm del conjugado dentro de las células, corroboró la utilidad de DenAuNP-Folato-Bombesina para la formación de imágenes ópticas. Después de la irradiación láser, la presencia del nanosistema en las células provocó un aumento significativo de la temperatura del medio (46.8 ◦ C, comparado con 39.1 ◦ C sin DenAuNP-Folato-Bombesina, p < 0.05), lo que resultó en una disminución significativa en la viabilidad celular (Hasta 16.51 ± 1.52 %) debido a las propiedades plasmónicas del 177LuDenAuNP-Folato-Bombesina. Después del tratamiento con el radiofármaco, la viabilidad celular T47D disminuyó 90 % debido a la dosis absorbida por radiación (63.16 ± 4.20 Gy) administrada dentro de las células. Se concluye que el 177Lu-DenAuNP-Folate-Bombesina internalizado en células de cáncer presenta propiedades adecuadas para la obtención de imágenes ópticas, terapia fototérmica-plasmónica y radioterapia dirigida.CONACYT (CONACYT-SEP-CB-2014-01-242443

Calentamiento de nanopartículas de oro inducido por excitación fotónica y multifotónica

Temperature generated by AuNPs when irradiated with laser, was evaluated to determine their usefulness in photonic plasmonic photothermal therapy or multiphotonic plasmonic photothermal therapy respectively. AuNPs were synthesized by the Turkevitch method and characterized by spectroscopic techniques. The AuNPs were irradiated by a Nd:YAG laser for 210 s, with 532 and 1 064 nm wavelength at 5, 10 and 15 Hz pulse repetition rate frequency. Temperature recording was carried out every second by a type-K thermocouple bounded to an Arduino UNO® card. AuNPs showed spherical shape, size of 20.7 + 0.2 nm and a maximum absorption peak of 520.16 + 0.93 nm. Irradiation at 1 064 nm exhibits higher temperature increase by 3.4, 1.9, and 1.2 times more than at 532 nm at the respective frequencies.Se evalúa la temperatura generada por nanopartículas de oro (AuNPs) al ser irradiadas con luz láser para su utilidad en terapia fototérmica plasmónica fotónica o multifotónica. Las AuNPs fueron sintetizadas por el método de Turkevitch y caracterizadas por técnicas espectroscópicas. La irradiación se realiza con un láser Nd:YAG, a longitudes de onda de 532 y 1 064 nm, frecuencias de repetición 5, 10 y 15 Hz durante 210 s. La temperatura fue medida con un termopar tipo K acoplado a una tarjeta Arduino UNO®. Las AuNPs muestran tamaños de 20.7 + 0.2 nm, forma esférica y un máximo de absorción UV-Vis en 520.16 + 0.93 nm. La irradiación a 1 064 nm exhibe mayor incremento de temperatura en 3.4, 1.9, y 1.2 veces más que a 532 nm a las respectivas frecuencias

Genotoxicity of Mercury and Its Derivatives Demonstrated In Vitro and In Vivo in Human Populations Studies. Systematic Review

Beside partial coverage in three reviews so far (1994, 2009, 2019), there is no review on genotoxic studies dealing with mercury (Hg) and human exposure using the most usual genotoxic assays: sister chromatid exchanges (SCE), chromosomal aberrations (CA), cytochalasin B blocked micronucleus assay (CBMN), and single-cell gel electrophoresis (SCGE or alkaline comet assay). Fifty years from the first Hg genotoxicity study and with the Minamata Convention in force, the genotoxic potential of Hg and its derivatives is still controversial. Considering these antecedents, we present this first systematic literature overview of genotoxic studies dealing with Hg and human exposure that used the standard genotoxic assays. To date, there is not sufficient evidence for Hg human carcinogen classification, so the new data collections can be of great help. A review was made of the studies available (those published before the end of October 2021 on PubMed or Web of Science in English or Spanish language) in the scientific literature dealing with genotoxic assays and human sample exposure ex vivo, in vivo, and in vitro. Results from a total of 66 articles selected are presented. Organic (o)Hg compounds were more toxic than inorganic and/or elemental ones, without ruling out that all represent a risk. The most studied inorganic (i)Hg compounds in populations exposed accidentally, occupationally, or iatrogenically, and/or in human cells, were Hg chloride and Hg nitrate and of the organic compounds, were methylmercury, thimerosal, methylmercury chloride, phenylmercuric acetate, and methylmercury hydroxide