Abstract The objective of this work is to analyze the partnership strategy of a company in stable conditions, to try to rescue other companies from the uncertainty caused by the COVID-19 pandemic. For this analysis, we relate the concepts of expected utility, risk, uncertainty and game theory, where the risk factor arises from the association with companies in possible failure, and the uncertainty factor from the lack of knowledge regarding the companies to associate. The results show that the conditions to be associated are different, depending on whether the objective is economic or precautionary. The contribution of the work is to methodologically analyze the concept of precaution, derived from the pandemic, that companies show when they decide to associate. Although the work does not consider information and real conditions of the pandemic, the work concludes and recommends that if companies decided to annex, to cover more market or recover, they would have to consider risk factors and uncertainty.

Resumen El objetivo de este trabajo es analizar la estrategia de asociación de una empresa en condiciones estables, para tratar de rescatar a otras empresas por la incertidumbre ocasionada por la pandemia del COVID-19. Para este análisis relacionamos los conceptos de utilidad esperada, riesgo, incertidumbre y teoría de juegos, donde el factor riesgo se desprende por la asociación con empresas en posible fracaso, y el factor incertidumbre por la falta de conocimiento respecto a las empresas a asociar. Los resultados muestran que las condiciones por asociar son distintas, dependiendo si el objetivo es económico o de precaución. La aportación del trabajo es analizar metodológicamente el concepto de precaución, derivado de la pandemia, que muestran las empresas cuando deciden asociarse. A pesar de que el trabajo no considera información y condiciones reales de la pandemia, el trabajo concluye y recomienda que si las empresas decidieran anexarse, para abarcar más mercado o recuperarse, tendrían que considerar factores de riesgo e incertidumbre.

Resumen El 25% de los pacientes con cáncer renal se presentan con enfermedad metastásica al momento del diagnóstico y un 30% de los pacientes con enfermedad localizada presentarán recurrencia de la enfermedad después de la nefrectomía. Es extremadamente rara, la actividad metastásica a vejiga, representando sólo el 1% de los tumores vesicales. Reportamos un caso de metástasis de carcinoma renal de células claras a vejiga siete años posterior al manejo inicial con nefrectomía radical. El manejo de la lesión metastásica fue mediante resección transuretral. La evidencia disponible sugiere que el tratamiento quirúrgico ofrece buenos resultados ya sea mediante resección transuretral, cistectomía parcial o radical. El pronóstico estará determinado por algunos factores pronósticos como el intervalo de tiempo entre el manejo inicial hasta la recurrencia, número y volumen de las lesiones metastásicas.

Abstract Twenty-five percent of patients with renal cancer initiate with metastatic disease at diagnosis and thirty percent of patients with localized disease present recurrence after nephrectomy. Metastatic activity to the bladder is extremely rare, representing only 1% of bladder tumors. We report a rare case of clear cell renal carcinoma metastasis to the bladder 7 years after initial management with radical nephrectomy. Management of the metastatic lesion was by transurethral resection. The available evidence suggests that surgical treatment offers good results, whether through transurethral resection, partial or radical cystectomy. The prognosis will be determined by some prognostic factors such as the time interval between initial management and recurrence, number and volume of metastatic lesions.

Abstract Objective: To present the results of our series of patients with lower third ureteral pathology, who underwent laparoscopic ureteral reimplantation in a tertiary care hospital. Material and methods: A retrospective study that included 18 patients with lower third ureteral pathology, treated with laparoscopic ureteral reimplantation, between July 2014 and December 2020. Demographic and clinical data, intraoperative results, complications, and days of hospital stay were collected, as well as postoperative control. Results: Transperitoneal Lich-Gregoir laparoscopic ureteral reimplantation was performed in 18 patients with lower third ureteral pathology (6 men and 12 women, 8 cases with right laterality and 10 left). Etiology: (11) 61% postsurgical stenosis, (2) 11% ureterovaginal fistula; (3) 17% vesicoureteral reflux, and (2) 11% congenital stricture. All cases had preoperative imaging studies. The mean age was 38.7 years; transoperative time 152 minutes; intraoperative bleeding of 65 ml. There were no intraoperative complications; The average hospital stay was 2.5 days. In all cases, a double J ureteral catheter was placed, which was removed 4 to 6 weeks after surgery. Conclusions: The laparoscopic ureteral reimplantation is a safe procedure for the treatment of lower third ureteral pathology. This modality seems to improve the profile of perioperative complications compared to the open approach, maintaining long-term results. The laparoscopic approach shows a decrease in surgical time, less bleeding, and a lower rate of complications and hospital stay, however, laparoscopic skills and experience must be available to perform it.

Resumen Objetivo: Presentar los resultados de nuestra serie de pacientes con patología ureteral de tercio inferior que se les realizó reimplante ureteral laparoscópico en un hospital de tercer nivel. Material y métodos: Estudio retrospectivo que incluyó 18 pacientes, con patología ureteral de tercio inferior tratados con reimplante ureteral laparoscópico, en un periodo comprendido de Julio 2014 a diciembre 2020. Se recolectaron datos demográficos, clínicos, resultados transoperatorios, complicaciones, días de estancia hospitalaria y control posoperatorio. Resultados: Se realizó reimplante ureteral laparoscópico Lich-Gregoir transperitoneal en 18 pacientes con patología ureteral de tercio inferior (6 hombres y 12 mujeres, 8 casos con lateralidad derecha y 10 izquierdos). La etiología: (11) 61 % estenosis posquirúrgica, (2) 11% fístula uretero-vaginal; (3) 17% reflujo vesicoureteral y (2) 11 % estenosis congénita. Todos los casos contaban con estudios de imagen preoperatorios. La media de edad fue 38.7 años; el tiempo transoperatorio 152 minutos; sangrado transoperatorio de 65 ml. No hubo complicaciones transoperatorias; La estancia hospitalaria promedio fueron 2.5 días. En todos los casos se colocó catéter ureteral doble j, el cual fue retirado a los 4 a 6 semanas posquirúrgicas. Conclusiones: El reimplante ureteral laparoscópico es un procedimiento seguro para el tratamiento de patología ureteral de tercio inferior. Dicha modalidad parece mejorar el perfil de complicaciones perioperatorias comparadas con el abordaje abierto, manteniendo los resultados a largo plazo. El abordaje laparoscópico demuestra una disminución del tiempo quirúrgico, menor sangrado, menor tasa de complicaciones y de estancia hospitalaria, sin embargo, se debe contar con las habilidades en laparoscopia y experiencia para realizarlo.

ABSTRACT OBJECTIVE: To describe the prevalence pattern of anemia among Indigenous children in Latin America. METHODS: PRISMA guidelines were followed. Records were identified from the databases PubMed, Google Scholar, and Lilacs by two independent researchers between May and June 2021. Studies were included if the following criteria were met: a) studied Indigenous people b) was about children (from 0 to 12 years old); c) reported a prevalence estimate of anemia; d) had been conducted in any of the countries of Latin America; e) was published either in English, Portuguese, or Spanish; f) is a peer-reviewed article; and g) was published at any date. RESULTS: Out of 2,401 unique records retrieved, 42 articles met the inclusion criteria. A total of 39 different Indigenous communities were analyzed in the articles, and in 21 of them (54.0%) child anemia was a severe public health problem (prevalence ≥ 40%). Those communities were the Aymara (Bolivia); Aruak, Guaraní, Kamaiurá, Karapotó, Karibe, Kaxinanuá, Ma-cro-Jê, Suruí, Terena, Xavante (Brazil); Cabécar (Costa Rica), Achuar, Aguaruna, Awajún, Urarina, Yomybato (Peru); Piaroa and Yucpa (Venezuela); and Quechua (Peru and Bolivia). Children below two years had the highest prevalence of anemia (between 16.2% and 86.1%). Among Indigenous people, risk factors for anemia include nutrition, poor living conditions, access to health services, racism, and discrimination. Bolivia and Guatemala are scarcely studied, despite having the highest proportion of Indigenous communities in Latin America. CONCLUSIONS: Anemia constitutes a poorly documented public health problem among Indigenous children in 21 Indigenous communities in Bolivia, Brazil, Colombia, Costa Rica, Ecuador, Guatemala, Mexico, and Peru. In all Indigenous communities included in this study child anemia was an issue, especially in younger children.

ABSTRACT OBJECTIVE: To describe the prevalence pattern of anemia among Indigenous children in Latin America. METHODS: PRISMA guidelines were followed. Records were identified from the databases PubMed, Google Scholar, and Lilacs by two independent researchers between May and June 2021. Studies were included if the following criteria were met: a) studied Indigenous people b) was about children (from 0 to 12 years old); c) reported a prevalence estimate of anemia; d) had been conducted in any of the countries of Latin America; e) was published either in English, Portuguese, or Spanish; f) is a peer-reviewed article; and g) was published at any date. RESULTS: Out of 2,401 unique records retrieved, 42 articles met the inclusion criteria. A total of 39 different Indigenous communities were analyzed in the articles, and in 21 of them (54.0%) child anemia was a severe public health problem (prevalence ≥ 40%). Those communities were the Aymara (Bolivia); Aruak, Guaraní, Kamaiurá, Karapotó, Karibe, Kaxinanuá, Ma-cro-Jê, Suruí, Terena, Xavante (Brazil); Cabécar (Costa Rica), Achuar, Aguaruna, Awajún, Urarina, Yomybato (Peru); Piaroa and Yucpa (Venezuela); and Quechua (Peru and Bolivia). Children below two years had the highest prevalence of anemia (between 16.2% and 86.1%). Among Indigenous people, risk factors for anemia include nutrition, poor living conditions, access to health services, racism, and discrimination. Bolivia and Guatemala are scarcely studied, despite having the highest proportion of Indigenous communities in Latin America. CONCLUSIONS: Anemia constitutes a poorly documented public health problem among Indigenous children in 21 Indigenous communities in Bolivia, Brazil, Colombia, Costa Rica, Ecuador, Guatemala, Mexico, and Peru. In all Indigenous communities included in this study child anemia was an issue, especially in younger children.

Resumen El objetivo del presente estudio fue caracterizar el ensilaje de maíz acorde a su composición química, a su rendimiento, así como a su producción de leche prevista. Se realizó una búsqueda en estudios relacionados al rendimiento del ensilado de maíz, a la densidad, a la composición química (MS, PB, FDN, almidón) y a la digestibilidad de materia seca (DMS). En este estudio fueron analizadas 41 variedades de maíz de regiones templadas y 101 variedades de maíz de origen tropical. Se determinaron la energía neta de lactancia (ENL Mcal/kg MS), los kilogramos de leche por t de ensilaje (kg de leche/t MS), y los kilogramos de leche por hectárea de ensilaje (kg de leche/ha). Se llevó a cabo un análisis cluster a partir del cual fueron obtenidos seis CL del ensilaje de maíz. El CL1 incluyó digestibilidad de materia seca, proteína bruta, fibra detergente neutro, ENL y kg de leche/t MS. El CL2 se caracterizó por ser el ensilaje de maíz con el mayor número de plantas por hectárea y FDN. El CL3 incluyó el mayor contenido de ceniza. El CL4 se compuso de valores intermedios en todas las variables. El CL5 incluyó el mayor rendimiento de forraje (t MS/ha) y kg de leche/ha, mientras que el CL6 incluyó el mayor kg de leche/t. En general, el CL1 fue el que presentó el mayor valor de DMS y ENL, produciendo como resultado más leche por t MS. Los resultados sugirieron que la opción ideal es el ensilaje de maíz con mayor rendimiento de forraje y más del 35 % MS (CL5), puesto que produjo más kg de leche por hectárea.

Abstract The objective of the present study was to characterize maize silage according to chemical composition, maize silage yield, as well as their predicted milk production. A search was made on studies related to maize silage yield, density, chemical composition (DM, CP, NDF, starch), and dry matter digestibility (DMD). In this study, 41 maize varieties from temperate regions and 101 maize varieties from tropical origin were analyzed. The net energy of lactation (NEL Mcal/kg DM), kilograms of milk per t of silage (kg of milk/t DM), and kilograms of milk per hectare of silage (kg of milk/ha) were determined. A cluster (CL) analysis was performed, and six CL of maize silage were obtained. The CL1 included digestibility for dry matter, crude protein, neutral detergent fiber, NEL, and kg of milk/t DM. CL2 was characterized by maize silage with the highest number of plants per hectare and NDF. CL3 included the highest ash content. CL4 consisted of intermediate values for all variables. CL5 included the highest forage yield (t DM/ha) and kg of milk/ ha whereas CL6 included the highest kg of milk/t. Overall, CL1 resulted in the highest DMD and NEL, producing more milk per t DM. Results suggested that the ideal option is maize silage with a higher forage yield and more than 35 % DM (CL5) since this produces more kg of milk per hectare.

Abstract Introduction The pandemic caused by SARS-Cov-2 has modified the teaching of medicine. The Structured Objective Clinical Examination (OSCE) is one of the strategies that has the greatest validity evidence to assess clinical competence, however, in Mexico there is no experience in applying it remotely (Web-OSCE). Objective To evaluate the degree of clinical competence of first-year resident physicians of the family medicine specialty through a Web-OSCE, comparing the origin of admission (ENARM vs ECA) and, according to the results, to be able to implement this remote evaluation. Method Observational and comparative study. The population consisted of 20 resident physicians, two groups were formed, 10 from the ENARM and 10 from the ECA, from various Health Institutions recognized by the Family Medicine Branch of the UNAM. The instrument used was a 4-station Web-ECOE. Results First-year family medicine residents generally show an acceptable degree of clinical competence in four common diseases of the first-level medical practice. The highest scores were for the diabetes mellitus and arterial hypertension stations and those with the lowest scores were the depression and obesity. Residents of the ENARM program scored better than residents of the ECA program. Conclusions The residents from the ENARM had better scores in clinical competencies than the residents from the ECA. Carrying out a Web-OSCE made it possible to assess the clinical competence of the residents. It is recommended to continue with the use of the Web-OSCE in graduate programs to assess clinical competence in a more comprehensive way.

Resumen Introducción La pandemia ocasionada por el SARS-Cov-2 ha modificado la enseñanza de la medicina. El Examen Clínico Objetivo Estructurado (ECOE), es una de las estrategias que cuenta con mayor evidencia de validez para evaluar la competencia clínica, sin embargo, en México no hay experiencia en aplicarla a distancia (Web-ECOE). Objetivo Evaluar el grado de competencia clínica de los médicos residentes de primer año de la especialidad de medicina familiar a través de un Web-ECOE comparando la procedencia de ingreso (ENARM vs ECA) y acorde con los resultados poder implementar esta evaluación a distancia. Método Estudio observacional comparativo. La población estuvo compuesta de 20 médicos residentes, se conformaron dos grupos, 10 provenientes del ENARM y 10 del ECA, de diversas Instituciones de Salud reconocidas por la Subdivisión de Medicina Familiar de la UNAM. El instrumento utilizado fue un Web-ECOE de 4 estaciones. Resultados Los residentes de primer año de medicina familiar muestran en general un grado aceptable de competencia clínica en cuatro enfermedades frecuentes de la consulta médica en el primer nivel de atención. Las puntuaciones mayores fueron para las estaciones de diabetes mellitus e hipertensión arterial y las de menor puntuación depresión y obesidad. Los residentes del programa ENARM obtuvieron mejores puntuaciones que los residentes del programa ECA. Conclusiones Los residentes provenientes del ENARM tuvieron mejores puntuaciones en las competencias clínicas que los residentes del ECA. Realizar un Web-ECOE permitió evaluar la competencia clínica de los residentes. Se recomienda continuar con el uso del Web-ECOE en los programas de posgrado para evaluar la competencia clínica en forma más integral.