Abstract This manuscript describes the organization, progress of the students and results of the Mexican MD/PhD program, explained as a case study. PECEM is the acronym for the Program of Combined Studies in Medicine that began in 2011 at the Faculty of Medicine of the National Autonomous University of Mexico (UNAM). PECEM is developed as a unique program, as an MD/PhD that includes a Bachelor’s and a Doctor of Medicine degree in a single curriculum in a period of eight years (16 semesters). Along with medical bachelor studies, PECEM students undertake seven research stays, with a duration of six months each, in several areas and with different advisers. After internship, the year of social service and five more semesters, they complete their doctoral thesis and graduate. Eleven students have already graduated (five from the first generation and six from the second generation); of these, 10 received their degree with honors and were already accepted in high quality institutions in different countries to continue their training as researchers or as specialized clinicians.

Resumen En este manuscrito se describe el programa, la organización, los avances de los estudiantes y resultados del MD/PhD mexicano, como un estudio de caso. PECEM es el acrónimo del Plan de Estudios Combinados en Medicina, que inició en 2011 en la Facultad de Medicina de la Universidad Nacional Autónoma de México (UNAM). El PECEM se desarrolla como un programa único, parecido al MD/PhD, que incluye la titulación de la licenciatura y la obtención del grado de doctor en medicina en un solo plan de estudios con una duración de ocho años (16 semestres). Se basa en que, durante la licenciatura de medicina, los alumnos del PECEM llevan a cabo siete estancias semestrales de investigación en diversas áreas y con tutores diferentes. Después del internado clínico, el año de servicio social y cinco semestres más, realizan su tesis doctoral y se gradúan. Hasta el momento, se han graduado 11 estudiantes (cinco de la primera generación y seis de la segunda generación), de estos, 10 recibieron mención honorífica y ya fueron aceptados en instituciones de alta calidad en diversos países para proseguir con su formación como investigadores o como médicos especialistas.

ABSTRACT Blastocystis sp. is a common intestinal microorganism. The α-L-fucosidase (ALFuc) is an enzyme long associated with the colonization of the gut microbiota. However, this enzyme has not been experimentally identified in Blastocystis cultures. The objective of the present study was to identify ALFuc in supernatants of axenic cultures of Blastocystis subtype (ST)1 ATCC-50177 and ATCC-50610 and to compare predicted ALFuc proteins of alfuc genes in sequenced STs1–3 isolates in human Blastocystis carriers. Excretion/secretion (Es/p) and cell lysate proteins were obtained by processing Blastocystis ATCC cultures and submitting them to SDS–PAGE and immunoblotting. In addition, 18 fecal samples from symptomatic Blastocystis human carriers were analyzed by sequencing of amplification products for subtyping. A complete identification of the alfuc gene and phylogenetic analysis were performed. Immunoblotting showed that the amplified band corresponding to ALFuc (~51 kDa) was recognized only in the ES/p. Furthermore, prediction analysis of ALFuc 3D structures revealed that the domain α-L-fucosidase and the GH29 family's catalytic sites were conserved; interestingly, the galactose-binding domain was recognized only in ST1 and ST2. The phylogenetic inferences of ALFuc showed that STs1–3 were clearly identifiable and grouped into specific clusters. Our results show, for the first time through experimental data that ALFuc is a secretion product of Blastocystis sp., which could have a relevant role during intestinal colonization; however, further studies are required to clarify this condition. Furthermore, the alfuc gene is a promising candidate for a phylogenetic marker, as it shows a conserved classification with the SSU-rDNA gene.

ABSTRACT The objective of this study was to estimate the direct costs associated with the diagnosis and treatment of neurocysticercosis (NCC) during pre-hospitalization, hospitalization, and post-hospitalization periods for 108 NCC patients treated at the Instituto Nacional de Neurologia y Neurocirugia (INNN) in Mexico City, Mexico. Information on clinical manifestations, diagnostic tests, hospitalizations, surgical procedures, prescription medication, and other treatments was collected via medical chart reviews. Uncertain values for costs and frequency of treatments were imputed using bootstrap techniques. The average per-patient pre-hospitalization and hospitalization costs were US$ 257 (95% CI: 185 – 329) and US$ 2,576 (95% CI: 2,244 – 2,908), respectively. Post-hospitalization costs tended to decrease over time, with estimates for the first five years post-hospitalization of US$ 475 (95% CI: 423 – 527), US$ 228 (95% CI: 167 – 288), US$ 157 (95% CI: 111 – 202), US$ 150 (95% CI: 106 – 204), and US$ 91 (95% CI: 27 – 154), respectively. NCC results in a significant economic burden for patients requiring hospitalization, with this burden continuing years post-hospitalization.

Introduction: Combined Studies in Medicine is a program in which outstanding students pursue a career in Medicine and simultaneously a doctorate. The requirements to complete the graduate course involve stress situations that could lead to burnout. Burnout is a syndrome with three dimensions: emotional exhaustion, cynicism and inefficiency, which can diminish the expectations of success, satisfaction and academic performance. Aim: To determine the frequency of burnout and its dimensions in students of six generations of the program as well as its correlation with habits, sociodemographic and academic characteristics. Subjects and methods: Students voluntarily answered a self-applied questionnaire and the Maslach Burnout Inventory-Student Survey. The prevalence of the dimensions and burnout were calculated and were correlated with variables evaluated in the questionnaire using the Fisher’s exact test. Results: The 56 participants were negative to burnout and 61% to the dimensions; 27% had inefficiency, 11% cynicism and 7% exhaustion, combined or alone. The prevalence of two dimensions was 5%. Significant differences were found (p< 0.05) for the relationship with colleagues, playing instruments, singing/acting, place of residence and violence on the way to the stay. Conclusions: The absence of burnout in the participants possibly reflects satisfaction and academic commitment. The bad relationship with colleagues and the violence on their way to the stay are frequent in students with exhaustion. It is possible that playing instruments, singing or acting was a response to exhaustion and cynicism, as well as other coping strategies not explored in this study.

Introducción: El Plan de Estudios Combinados en Medicina está diseñado para que alumnos sobresalientes que cursan la carrera de medicina estudien el doctorado simultáneamente. Las exigencias para culminar el posgrado involucran situaciones de estrés que podrían llevar al desgaste. El burnout es un síndrome con tres dimensiones: agotamiento emocional, cinismo e ineficacia, que pueden disminuir las expectativas de éxito, satisfacción y rendimiento académico. Objetivo: Determinar la frecuencia de burnout y sus dimensiones en estudiantes de seis generaciones del programa, así como su correlación con características sociodemográficas, académicas y hábitos. Sujetos y métodos: Los alumnos respondieron voluntariamente un cuestionario autoaplicado y el Maslach Burnout Inventory-Student Survey. Se calculó la prevalencia de las dimensiones del burnout y se correlacionaron con variables evaluadas en el cuestionario usando la prueba exacta de Fisher. Resultados: Los 56 participantes no presentaron burnout y un 61% tampoco las dimensiones del síndrome. Solas o combinadas, un 27% mostró ineficacia; un 11%, cinismo, y un 7%, agotamiento. La prevalencia de dos dimensiones fue del 5%. Se encontraron diferencias significativas (p< 0,05) para la relación con el grupo, tocar un instrumento, cantar o actuar, sitio de residencia y la violencia en el traslado. Conclusiones: La ausencia de burnout en los participantes posiblemente refleja satisfacción y compromiso académico. La pésima relación con compañeros y la violencia en el traslado son frecuentes en alumnos con agotamiento. Es posible que tocar un instrumento, cantar o actuar constituya una respuesta al agotamiento y al cinismo, así como otras estrategias de afrontamiento no exploradas en este estudio.

The study described here was performed in a suburban community of the Estado de México to Echinococcus spp, since a human case of cystic echinococcosis (CE) was identified previously. Overall, 91% (406/446) of the houses were visited and oral informed consent was obtained from dog owners; a questionnaire related to their dogs was applied and a coprological sample was obtained. It was found that 14% of dog owners fed them with raw livestock viscera. Coprological studies showed that eggs of Ancylostoma and Toxocara were the most abundant, thus deworming was recommended to all owners. Dogs with Taenia spp eggs were treated and Taenia pisiformis adults were released, not from Echinococcus spp. Most sheep in the community were studied by ultrasound and viscera of those slaughtered, were visually inspected; confirming the absence of CE. Interestingly, although no evidences of Echinococcus spp were found in animals, an autochthonous human case of CE was detected in 2006; this, added to proper practices for maintaining the life cycle of this parasite, suggests that echinococcosis in Mexico has a random behavioral pattern.

El presente estudio se llevó a cabo en una comunidad suburbana del Estado de México para identificar Echinococcus spp, debido a que en un estudio previo se identificó un caso de equinococosis quística (EQ) humana. Se visitaron 91% (406/446) de las viviendas y se obtuvo el consentimiento verbal de los propietarios de perros; se aplicó un cuestionario relacionado con sus animales y se obtuvo una muestra de heces. Se encontró que 14% de los dueños de perros los alimentaban con visceras crudas de animales de abasto; este resultado no tuvo significancia estadística. Los estudios coprológicos mostraron abundantes huevos de Ancylostoma y Toxocara, por lo que se recomendó a los propietarios la desparasitación de sus animales. Aquellos perros que tenían huevos de Taenia spp fueron desparasitados y se recuperaron adultos de Taenia pisiformis, no de Echinococcus spp. La mayoría de los borregos de la comunidad se estudiaron por ultrasonido, y las visceras de aquéllos que fueron sacrificados se examinaron durante la necropsia; en ambos casos se confirmó la ausencia de EQ. Llama la atención que aunque no se encontraron evidencias de Echinococcus spp en animales, el antecedente de un caso humano autóctono de EQ, sumado a prácticas propicias para el mantenimiento del ciclo de vida de este parásito, sugieren que la equinococosis en México tiene un patrón de comportamiento aleatorio.

Human neurocysticercosis is a disease associated with underdevelopment and occurs in countries with poor health infrastructure and poor health education. Despite the fact that human cysticercosis is considered a neglected disease, in this paper the events that have facilitated its control in Mexico are described. Therefore, it can be considered that neurocysticercosis may no longer be a public health problem in our country.

La neurocisticercosis humana es una enfermedad que se relaciona con el subdesarrollo, se presenta en países que no tienen buena infraestructura sanitaria ni educación para la salud. A pesar de que la cisticercosis humana se considera como una enfermedad desatendida, en este trabajo se describen los sucesos que han facilitado su control en México, por lo que se puede afirmar que la neurocisticercosis ya no es una enfermedad de importancia en salud pública en nuestro país.

Mexican and Colombian Taenia solium cysticerci and some species of Taenia adults were assayed using cellulose acetate electrophoresis to distinguish between isolates. Isozyme patterns for ARK, GOT, G3PD, GPI, and MPI were identical in all cysticerci suggesting homozygotic profiles. G6PD and MDH showed different patterns between Mexican and Colombian cysticerci, suggesting regional differences. ME activity was mainly detected in the adult stage suggesting that this enzyme is active in anaerobic environment, while MDH, detected in cysticerci, could be related to an environment that contains oxygen. Finally, the species of taeniid adults analyzed showed different patterns among them.

Objective. To evaluate cytology laboratories and the performance of cytotechnologists for establishing efficient external quality control for Mexico's National Program for the Prevention and Control of Cervical Cancer. Material and Methods. During January and February 1998, an on-site evaluation of all cytology laboratories of the Ministry of Health found that only 70% of the microscopes were in adequate working conditions, reagents were out of date, and working conditions were sub-optimal. A program for external quality control based on proficiency testing was established for cytotechnologists. Fifty slide sets with 20 Papanicolaou slides and 10 photographic slides were prepared. The sets were given to the cytotechnologists for evaluation and again one year later by courier. Results. Twenty-one percent of microscopes were repaired and 9% replaced; reagents were distributed and laboratory facilities improved. Only 16% of cytotechnologists passed the initial proficiency test. Cytotechnologists received a refresher training course: one year later 67% of them passed the proficiency test. To ascertain that each slide was correctly diagnosed, 41 sets were rescreened by expert cytopathologists or cytologists and their diagnoses compared to the original ones. Thirty-seven sets had 86% to 96% concordance. Conclusions. This new system for external quality control of cervical cytology allowed the opportune and reliable evaluation of the performance of cytotechnologists.

Objetivo. Evaluar los laboratorios de citología y la capacidad de los citotecnólogos para establecer un programa eficiente de control de calidad externo para el Programa Nacional de Prevención y Control de Cáncer Cérvico Uterino de México. Material y métodos. Se realizó una evaluación de todos los laboratorios de citología de la Secretaría de Salud; sólo 70% de los microscopios estaban en buenas condiciones de trabajo, había reactivos caducos y condiciones subóptimas de trabajo. Se estableció un programa de control de calidad externo basado en pruebas de eficiencia para los citotecnólogos. Se elaboraron 50 conjuntos con 20 laminillas de Papanicolaou y 10 diapositivas. Los conjuntos se enviaron a los citotecnólogos para su evaluación in situ y un año después se remitieron nuevamente por mensajería. Resultados. De los microscopios, 21% se reparó y 9% fueron remplazados; se distribuyeron reactivos y se mejoraron algunos laboratorios. Debido a que sólo 16% de los citotecnólogos aprobó la evaluación inicial, se organizaron cursos intensivos de capacitación y un año después 67% de ellos aprobaron. Para asegurar que cada laminilla tuviera un diagnóstico correcto, los citopatólogos o citólogos expertos revisaron nuevamente 41 conjuntos y sus diagnósticos se compararon con los originales; 37 conjuntos tuvieron 86 a 96% de concordancia. Conclusiones. Este nuevo sistema de control de calidad externo de citología cervical permitió tener una evaluación oportuna y confiable de la capacidad de los citotecnólogos.

Objective. To evaluate cytology laboratories and the performance of cytotechnologists for establishing efficient external quality control for Mexico's National Program for the Prevention and Control of Cervical Cancer. Material and Methods. During January and February 1998, an on-site evaluation of all cytology laboratories of the Ministry of Health found that only 70% of the microscopes were in adequate working conditions, reagents were out of date, and working conditions were sub-optimal. A program for external quality control based on proficiency testing was established for cytotechnologists. Fifty slide sets with 20 Papanicolaou slides and 10 photographic slides were prepared. The sets were given to the cytotechnologists for evaluation and again one year later by courier. Results. Twenty-one percent of microscopes were repaired and 9% replaced; reagents were distributed and laboratory facilities improved. Only 16% of cytotechnologists passed the initial proficiency test. Cytotechnologists received a refresher training course: one year later 67% of them passed the proficiency test. To ascertain that each slide was correctly diagnosed, 41 sets were rescreened by expert cytopathologists or cytologists and their diagnoses compared to the original ones. Thirty-seven sets had 86% to 96% concordance. Conclusions. This new system for external quality control of cervical cytology allowed the opportune and reliable evaluation of the performance of cytotechnologists.

Objetivo. Evaluar los laboratorios de citología y la capacidad de los citotecnólogos para establecer un programa eficiente de control de calidad externo para el Programa Nacional de Prevención y Control de Cáncer Cérvico Uterino de México. Material y métodos. Se realizó una evaluación de todos los laboratorios de citología de la Secretaría de Salud; sólo 70% de los microscopios estaban en buenas condiciones de trabajo, había reactivos caducos y condiciones subóptimas de trabajo. Se estableció un programa de control de calidad externo basado en pruebas de eficiencia para los citotecnólogos. Se elaboraron 50 conjuntos con 20 laminillas de Papanicolaou y 10 diapositivas. Los conjuntos se enviaron a los citotecnólogos para su evaluación in situ y un año después se remitieron nuevamente por mensajería. Resultados. De los microscopios, 21% se reparó y 9% fueron remplazados; se distribuyeron reactivos y se mejoraron algunos laboratorios. Debido a que sólo 16% de los citotecnólogos aprobó la evaluación inicial, se organizaron cursos intensivos de capacitación y un año después 67% de ellos aprobaron. Para asegurar que cada laminilla tuviera un diagnóstico correcto, los citopatólogos o citólogos expertos revisaron nuevamente 41 conjuntos y sus diagnósticos se compararon con los originales; 37 conjuntos tuvieron 86 a 96% de concordancia. Conclusiones. Este nuevo sistema de control de calidad externo de citología cervical permitió tener una evaluación oportuna y confiable de la capacidad de los citotecnólogos.

Objective. To determine the prevalence and risk factors associated to pig cysticercosis in a rural community of Veracruz, Mexico. Material and Methods. Swine cysticercosis was diagnosed by tongue palpation and circulating antibodies in pigs kept in 178 household backyards. Risk factors were assessed by interviewing owners to collect information on pig breeding conditions and demographic characteristics. Results. None of the 53 pigs studied showed cysts in the tongue, nor antibodies against Taenia solium in Western blot assays. Latrines were available in 91% of the houses and pigs were kept in restrained areas. Conclusions. The present study shows that pig breeding under restraint with basic hygiene and sanitary conditions, may be effective and practical interventions to restrain Taenia solium in rural communities. The English version of this paper is available too at: <A HREF="http://www.insp.mx/salud/index.html">http://www.insp.mx/salud/index.html </A>

Objetivo. Determinar la prevalencia y factores de riesgo asociados con cisticercosis porcina en una población rural de Veracruz, México. Material y métodos. Se diagnosticó cisticercosis porcina por medio de palpación lingual y anticuerpos circulantes en cerdos de traspatio en 178 casas. Se analizaron los factores de riesgo mediante una encuesta a los dueños respecto a las condiciones de crianza de los cerdos y sus características demográficas. Resultados. Los 53 cerdos estudiados fueron negativos al metacéstodo de Taenia solium por palpación lingual y para la presencia de anticuerpos contra este agente por inmunoelectrotransferencia. El 91% de las casas contaban con letrinas y los cerdos estaban confinados en zonas restringidas. Conclusiones. Este estudio muestra que el confinamiento de cerdos puede explicar la ausencia de Taenia solium en comunidades rurales, y sugiere que es factible y práctico establecer medidas de intervención. El texto completo en inglés de este artículo también está disponible en: <A HREF="http://www.insp.mx/salud/index.html">http://www.insp.mx/salud/index.html</A>

Objective. To determine the prevalence and risk factors associated to pig cysticercosis in a rural community of Veracruz, Mexico. Material and Methods. Swine cysticercosis was diagnosed by tongue palpation and circulating antibodies in pigs kept in 178 household backyards. Risk factors were assessed by interviewing owners to collect information on pig breeding conditions and demographic characteristics. Results. None of the 53 pigs studied showed cysts in the tongue, nor antibodies against Taenia solium in Western blot assays. Latrines were available in 91% of the houses and pigs were kept in restrained areas. Conclusions. The present study shows that pig breeding under restraint with basic hygiene and sanitary conditions, may be effective and practical interventions to restrain Taenia solium in rural communities. The English version of this paper is available too at: <A HREF="http://www.insp.mx/salud/index.html">http://www.insp.mx/salud/index.html </A>

Objetivo. Determinar la prevalencia y factores de riesgo asociados con cisticercosis porcina en una población rural de Veracruz, México. Material y métodos. Se diagnosticó cisticercosis porcina por medio de palpación lingual y anticuerpos circulantes en cerdos de traspatio en 178 casas. Se analizaron los factores de riesgo mediante una encuesta a los dueños respecto a las condiciones de crianza de los cerdos y sus características demográficas. Resultados. Los 53 cerdos estudiados fueron negativos al metacéstodo de Taenia solium por palpación lingual y para la presencia de anticuerpos contra este agente por inmunoelectrotransferencia. El 91% de las casas contaban con letrinas y los cerdos estaban confinados en zonas restringidas. Conclusiones. Este estudio muestra que el confinamiento de cerdos puede explicar la ausencia de Taenia solium en comunidades rurales, y sugiere que es factible y práctico establecer medidas de intervención. El texto completo en inglés de este artículo también está disponible en: <A HREF="http://www.insp.mx/salud/index.html">http://www.insp.mx/salud/index.html</A>

Taenia solium is a parasite that causes human cysticercosis. Its life cycle includes the adult stage, the egg and the larval stage. Human cysticercosis is a disease related to underdevelopment, the main clinical manifestation is neurocysticercosis. Control measures include mass cestocidal treatment aimed to cure possible taeniosis cases. Although useful it has certain disadvantages, such as the generation of symptomatology in occult neurocysticercosis. Alternatively, health education has been shown to be highly effective since people become aware of the importance of human and porcine cysticercosis and the possibility of eliminating it. Nevertheless it has to be implemented by knowledgeable people. On the other hand, the life cycle can be controlled by avoiding swine cysticercosis. This review describes the studies performed to vaccinate pigs against T. solium and indicate that short time perspectives are very encouraging for the production of an optimal vaccine.