A survey of Senecio spp. affecting livestock in Uruguay and their associated pyrrolizidine alkaloid content / Senecio spp. Afetando a pecuária no Uruguai e sua associação com alcaloides pirrolizidínicos

ABSTRACT: In Eastern Uruguay there has been a significant increase of seneciosis in grazing livestock with most affected localities related to counties neighboring the Brazilian border. A survey in 28 farms associated with poisoning outbreaks in grazing cattle in Eastern Uruguay was carried out. Fifty populations of Senecio plants were collected for alkaloid analysis and species identification. Four species were identified: S. oxyphyllus DC, S. madagascariensis Poir, S. brasiliensis (Spreng.) Less., and S. selloi DC. Alkaloids were identified by a combination of GC-MS and HPLC-MS analysis and included: retrorsine in S. oxyphyllus; retrorsine, usaramine, and senecivernine/senecionine in S. selloi; retrorsine, senecivernine/senecionine, integerrimine, and usaramine in S. madagascariensis; and integerrimine, retrorsine and senecionine in S. brasiliensis. Total mean alkaloid concentration was reported to be highest in S. brasiliensis (17.6mg/g) followed by S. oxyphyllus (6.2mg/g), S. selloi (1.8mg/g) and S. madagascariensis (0.6mg/g). Alkaloid concentrations were also reported to be higher in 2015 vs. 2016 probably due to a common environmental factor. The species S. oxyphyllus and S. madagascariensis were not previously recognized as toxic plants in Eastern Uruguay. Particularly, S. oxyphyllus was present in 82% of the farms surveyed and occurred in high density with relative high concentrations of pyrrolizidine alkaloids suggesting S. oxyphyllus may be the main species involved in the reported outbreaks of seneciosis.

RESUMO: No leste do Uruguai houve um aumento significativo da seneciosis no gado de pastagem com a maioria das localidades afetadas em municípios vizinhos à fronteira brasileira. Aplicou-se um questionário em 28 fazendas associadas a surtos de intoxicação em bovinos de pastagem na fronteira leste do Uruguai. Coletaram-se cinquenta populações de Senecio para análise de alcalóides e identificação de espécies. Identificaram-se quatro espécies: S. oxyphyllus DC, S. madagascariensis Poir, S. brasiliensis (Spreng.) Less. e S. selloi DC. Identificaram-se os seguintes alcalóides mediante análise combinado de GC-MS e HPLC-MS: retrorsina em S. oxyphyllus; retrorsina, usaramina e senecivernina/senecionina em S. selloi; retrorsina, senecivernina/senecionina, integerimina e usaramina em S. madagascariensis; e integerrimina, retrorsina e senecionina em S. brasiliensis. A concentração média total de alcalóides foi mais elevada em S. brasiliensis (17,6mg/g) seguido de S. oxyphyllus (6,2mg/g), S. selloi (1,8mg/g) e S. madagascariensis (0,6mg/g). As concentrações de alcaloides foram maiores em 2015 em vista à 2016, provavelmente, devido a um fator ambiental comum. As espécies S. oxyphyllus e S. madagascariensis não foram previamente reconhecidas como plantas tóxicas no leste do Uruguai. Particularmente, S. oxyphyllus esteve presente em 82% das fazendas pesquisadas e ocorreu em alta densidade com concentrações relativamente elevadas de alcalóides de pirrolizidina sugerindo que S. oxyphyllus pode ser a principal espécie envolvida nos surtos relatados de seneciosis.

Vitamin D supplementation for women during pregnancy

ABSTRACT BACKGROUND: Vitamin D deficiency or insufficiency is thought to be common among pregnant women. Vitamin D supplementation during pregnancy has been suggested as an intervention to protect against adverse pregnancy outcomes. OBJECTIVES: To examine whether oral supplements with vitamin D alone or in combination with calcium or other vitamins and minerals given to women during pregnancy can safely improve maternal and neonatal outcomes. METHODS: Search methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (23 February 2015), the International Clinical Trials Registry Platform (31 January 2015), the Networked Digital Library of Theses and Dissertations (28 January 2015) and also contacted relevant organisations (31 January 2015). Selection criteria: Randomized and quasi-randomized trials with randomization at either individual or cluster level, evaluating the effect of supplementation with vitamin D alone or in combination with other micronutrients for women during pregnancy. Data collection and analysis: Two review authors independently i) assessed the eligibility of studies against the inclusion criteria ii) extracted data from included studies, and iii) assessed the risk of bias of the included studies. Data were checked for accuracy. The quality of the evidence was assessed using the GRADE approach. MAIN RESULTS: In this updated review we included 15 trials assessing a total of 2833 women, excluded 27 trials, and 23 trials are still ongoing or unpublished. Nine trials compared the effects of vitamin D alone versus no supplementation or a placebo and six trials compared the effects of vitamin D and calcium with no supplementation. Risk of bias in the majority of trials was unclear and many studies were at high risk of bias for blinding and attrition rates. Vitamin D alone versus no supplementation or a placebo Data from seven trials involving 868 women consistently show that women who received vitamin D supplements alone, particularly on a daily basis, had higher 25-hydroxyvitamin D than those receiving no intervention or placebo, but this response was highly heterogeneous. Also, data from two trials involving 219 women suggest that women who received vitamin D supplements may have a lower risk of pre-eclampsia than those receiving no intervention or placebo (8.9% versus 15.5%; risk ratio (RR) 0.52; 95% CI 0.25 to 1.05, low quality). Data from two trials involving 219 women suggest a similar risk of gestational diabetes among those taking vitamin D supplements or no intervention/placebo (RR 0.43; 95% CI 0.05, 3.45, very low quality). There were no clear differences in adverse effects, with only one reported case of nephritic syndrome in the control group in one study (RR 0.17; 95% CI 0.01 to 4.06; one trial, 135 women, low quality). Given the scarcity of data for this outcome, no firm conclusions can be drawn. No other adverse effects were reported in any of the other studies. With respect to infant outcomes, data from three trials involving 477 women suggest that vitamin D supplementation during pregnancy reduces the risk preterm birth compared to no intervention or placebo (8.9% versus 15.5%; RR 0.36; 95% CI 0.14 to 0.93, moderate quality). Data from three trials involving 493 women also suggest that women who receive vitamin D supplements during pregnancy less frequently had a baby with a birthweight below 2500 g than those receiving no intervention or placebo (RR 0.40; 95% CI 0.24 to 0.67, moderate quality). In terms of other outcomes, there were no clear differences in caesarean section (RR 0.95; 95% CI 0.69 to 1.31; two trials; 312 women); stillbirths (RR 0.35 95% CI 0.06, 1.99; three trials, 540 women); or neonatal deaths (RR 0.27; 95% CI 0.04, 1.67; two trials, 282 women). There was some indication that vitamin D supplementation increases infant length (mean difference (MD) 0.70, 95% CI -0.02 to 1.43; four trials, 638 infants) and head circumference at birth (MD 0.43, 95% CI 0.03 to 0.83; four trials, 638 women). Vitamin D and calcium versus no supplementation or a placebo Women who received vitamin D with calcium had a lower risk of pre-eclampsia than those not receiving any intervention (RR 0.51; 95% CI 0.32 to 0.80; three trials; 1114 women, moderate quality), but also an increased risk of preterm birth (RR 1.57; 95% CI 1.02 to 2.43, three studies, 798 women, moderate quality). Maternal vitamin D concentration at term, gestational diabetes, adverse effects and low birthweight were not reported in any trial or reported only by one study. AUTHORS CONCLUSIONS: New studies have provided more evidence on the effects of supplementing pregnant women with vitamin D alone or with calcium on pregnancy outcomes. Supplementing pregnant women with vitamin D in a single or continued dose increases serum 25-hydroxyvitamin D at term and may reduce the risk of pre-eclampsia, low birthweight and preterm birth. However, when vitamin D and calcium are combined, the risk of preterm birth is increased. The clinical significance of the increased serum 25-hydroxyvitamin D concentrations is still unclear. In light of this, these results need to be interpreted with caution. Data on adverse effects were lacking in all studies. The evidence on whether vitamin D supplementation should be given as a part of routine antenatal care to all women to improve maternal and infant outcomes remains unclear. While there is some indication that vitamin D supplementation could reduce the risk of pre-eclampsia and increase length and head circumference at birth, further rigorous randomized trials are required to confirm these effects.

Consideraciones sobre la elaboración de las directrices de nutrición de la Organización Mundial de la Salud y su implementación / Considerations on the development of nutrition-related guidelines by the World Health Organization and their implementation

La Organización Mundial de la Salud (OMS) sigue un proceso complejo y riguroso para la elaboración de directrices mundiales. En el caso de las directrices relacionadas con nutrición, la participación conjunta de las autoridades de los Estados Miembros de la OMS y sus aliados, incluidos aquellos de la economía social y solidaria, es clave para fortalecer el proceso de elaboración de directrices informadas por las pruebas científicas y su posterior implementación, como parte de las estrategias nacionales de salud pública. Para las autoridades en materia de salud y desarrollo social, la OMS desarrolla una serie de herramientas para la formulación de políticas informadas por las pruebas científicas, considerando su pertinencia, relevancia e implementabilidad. Este proceso de adopción y adaptación debe considerar aspectos de equidad, para evitar la ampliación de brechas en salud. Las directrices mundiales de la OMS contribuyen a que las intervenciones en nutrición en sus Estados Miembros sean implementadas de manera adecuada. Dos experiencias de implementación de intervenciones en nutrición, una en Panamá y otra en Perú, ejemplifican este proceso. El artículo concluye sugiriendo profundizar en el conocimiento y aplicación de la investigación de la implementación de programas para identificar los factores que permiten a una intervención ser efectiva, tener una mejor estrategia de escalabilidad y contribuir a la equidad en salud.

The World Health Organization (WHO) follows a complex and rigorous process to develop global guidelines. With regard to nutrition-related guidelines, the joint participation of national authorities from Member States and their partners, including those of the social economy, is key to strengthening the process of evidence-informed guideline development and the subsequent implementation as part of national public health strategies. WHO puts forward a series of tools that can assist national authorities on health and social development in the elaboration of evidenceinformed policies, considering their pertinence, relevance and implementability. This adoption and adaptation process must consider equity in order to avoid widening existing inequities. WHO global nutrition guidelines contribute to the effective implementation of nutrition interventions in Member States. Two experiences of implementation, one in Panama and one in Peru, exemplify this process. The paper ends by suggesting a deeper understanding and utilization of implementation research during programmes to identify what factors ensure effective interventions, appropriate scale up strategies and greater health equity.

Metas globales de la organización mundial de la salud para mejorar la nutrición materna, del lactante y del niño pequeño / World Health Organization's global targets on maternal, infant and young child nutrition

La Asamblea Mundial de la Salud es el órgano decisorio supremo de la Organización Mundial de la Salud. Se reúne en Ginebra en Mayo de cada año con la asistencia de delegaciones de los Estados Miembros. La 65a Asamblea Mundial de la Salud realizada en Ginebra del 21 al 26 de Mayo de 2012, aprobó el Plan de Aplicación Integral sobre Nutrición de la Madre, el Lactante y el Niño Pequeño, el cual incluye seis metas globales fundamentales para lograr mejorías en relación con: el retraso en el crecimiento (talla baja para la edad) en niños, la anemia en mujeres en edad reproductiva, el bajo peso al nacer, el sobrepeso en niños, la lactancia materna exclusiva y la emaciación en menores de cinco años hasta el año 2025. Las metas globales fueron endosadas por los Países Miembros de la Organización Mundial de la Salud quienes se comprometieron a monitorear y hacer seguimiento del progreso hacia el alcance de las metas. Estas metas permiten identificar las áreas prioritarias de acción y propiciar cambios a nivel mundial. Este articulo describe cuáles son las metas globales y las herramientas disponibles para monitorear a nivel nacional los indicadores propuestos. Los resultados del instrumento de seguimiento desarrollado por la OMS se incorporarán en el informe mundial de nutrición que actualmente prepara un grupo independiente de expertos(AU)

The World Health Assembly is the supreme decision-making body of the World Health Organization. It meets every year in May in the city of Geneva and is attended by delegations of Member States. The 65th World Health Assembly held from the 21st to 26th of May 2012, approved the Comprehensive Implementation Plan on Maternal, Infant and Young Child Nutrition, which includes six key global targets to achieve improvements in: the stunting (low height for age) in children, anemia in women of reproductive age, low birth weight, overweight in children, exclusive breastfeeding, and wasting in children under five years by the year 2025. These goals were endorsed by the Member States of the World Health Organization who pledged to monitor and track the progress for achievements. The goals help to identify priority areas for action and foster global change. This article describes the six global goals and the tools that are available for adaptation at the national level and for monitoring progress indicators proposed by the Member States. The results of the monitoring tool developed by WHO will be incorporated in the world nutrition report which is being prepared by an independent group of experts(AU)

One-step, codominant detection of imidazolinone resistance mutations in weedy rice (Oryza sativa L. )

Background Weedy rice (Oryza sativa L.) is a noxious form of cultivated rice (O. sativa L.) associated with intensive rice production and dry seeding. A cost-efficient strategy to control this weed is the Clearfield rice production system, which combines imidazolinone herbicides with mutant imidazolinone-resistant rice varieties. However, imidazolinone resistance mutations can be introgressed in weedy rice populations by natural outcrossing, reducing the life span of the Clearfield technology. Timely and accurate detection of imidazolinone resistance mutations in weedy rice may contribute to avoiding the multiplication and dispersion of resistant weeds and to protect the Clearfield system. Thus, highly sensitive and specific methods with high throughput and low cost are needed. KBioscience's Allele Specific PCR (KASP) is a codominant, competitive allele-specific PCR-based genotyping method. KASP enables both alleles to be detected in a single reaction in a closed-tube format. The aim of this work is to assess the suitability and validity of the KASP method for detection in weedy rice of the three imidazolinone resistance mutations reported to date in rice. Results Validation was carried out by determining the analytical performance of the new method and comparing it with conventional allele-specific PCR, when genotyping sets of cultivated and weedy rice samples. The conventional technique had a specificity of 0.97 and a sensibility of 0.95, whereas for the KASP method, both parameters were 1.00. Conclusions The new method has equal accuracy while being more informative and saving time and resources compared with conventional methods, which make it suitable for monitoring imidazolinone-resistant weedy rice in Clearfield rice fields.

Valores de referencia de hierro, yodo, zinc, selenio, cobre, molibdeno, vitamina C, vitamina E, vitamina K, carotenoides y polifenoles para la población venezolana / Reference values of iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols for the Venezuelan population

Esta revisión de las recomendaciones de energía y nutrientes para la población Venezolana presenta los valores de hierro, yodo, zinc, selenio, cobre, molibdeno, vitamina C, vitamina E, vitamina K, carotenoides y polifenoles. Se adoptan definiciones internacionales de Ingestas Dietéticas de Referencia (DRIs por Dietary Reference Intakes) que incluyen: Ingesta Dietética Recomendada (RDA), Requerimiento Promedio Estimado (EAR), Ingesta Adecuada (AI) y Niveles de Ingesta Máximos Tolerables (UL). Las RDA para hierro: 11 mg/día para < 1 año, 7-10 mg/día niños, 8-11 mg/día para hombres, 8-18 mg/día para mujeres y 27 mg/día para embarazadas. RDA Yodo: 110-130 mg/ día recién nacidos, 90-120 mg/día niños y adolescentes y 150 mg/ día adultos, 220 mg/día embarazo y 290 mg/día lactancia. RDA Zinc: 2-3 mg/día < 1 año, 3-5 mg/día niños, 8-11 mg/día adolescentes y hombres, 8-9 mg/día adolescentes y mujeres, 12 mg/ día para embarazadas y 13 mg/día durante la lactancia. RDA Vitamina C: 40-50 mg/día recién nacidos, 15-45 mg/día niños, 75 mg/día adolescentes masculinos, 65 mg/día adolescentes femeninas, 90 mg/día hombres y 75 mg/día mujeres, 80-85 mg/día embarazadas y lactancia 115-120 mg/día. También se presentan valores de cobre, selenio, molibdeno, vitaminas E, K, carotenoides y polifenoles. Estas recomendaciones contribuirán al diseño de políticas adecuadas y eficientes que puedan ayudar a evitar o a tratar las consecuencias derivadas de la deficiencia o el exceso de estos nutrientes.

The review on iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols recommendations for Venezuela comprise the definitions adopted worldwide known as Dietary Reference Intakes (DRIs) that include Recommended Dietary Allowance (RDA), Estimated Average Requirement (EAR), Adequate Intake (AI) and Tolerable Upper Intake Levels (UL). The RDA for iron: 11 mg/day for infants < 1 year of age, 7 - 10 mg/day for children, 8-11 mg/day for males, 8-18 mg/day for females and 27 mg/day during pregnancy. RDA for iodine: 110-130 mg/day for infants, 90-120 mg/ day for children and adolescents, 150 mg/day for adults, 220 mg/ day for pregnancy and 290 mg/day during lactation. RDA Zinc: 2-3 mg/day for infants, 3-5 mg/day for children, 8-11 mg/day for male adolescents and adults, 8-9 mg/day for female adolescents and adults, 12 mg/day during pregnancy and 13 mg/day for lactation. RDA Vitamin C: 40-50 mg/day for infants, 15-45 mg/ day for children, 75 mg/day for male adolescents, 65 mg/day for female adolescents, 90 mg/day for adult males, 75 mg/day for adult females, 80-85 mg/day during pregnancy and 115-120 mg/ day during lactation. Recommendations for copper, selenium, molybdenum, vitamins E, K, carotenoids and polyphenols are also presented. These recommendations will help to design adequate and efficient policies that could help to avoid or to treat the consequences derived from the deficiency or the excess of these nutrients.

An evaluation of a global vitamin and mineral nutrition surveillance system / Evaluación de un sistema global de vigilancia nutricional sobre vitaminas y minerales

Evaluation at all levels is a fundamental function at World Health Organization (WHO). Evaluation of public health surveillance systems is essential to ensure that problems of public health importance are monitored efficiently and effectively. The WHO's Vitamin and Mineral Nutrition Information System (VMNIS) was evaluated from the perspective of public health surveillance and informatics. Steps included: engaging the stakeholders of the evaluation; describing the surveillance system; focusing the evaluation design; gathering credible evidence regarding system performance; justifying and stating conclusions and recommendations, and sharing lessons learned from the evaluation. Following this assessment, WHO has begun major efforts to upgrade and expand the VMNIS and now the database is more flexible and efficient. The database evaluation summarized in this paper provides a good example of how public health evaluation frameworks can lead to improved surveillance and enhanced information systems, thus making progress toward the ultimate goal of improving public health.

La evaluación en todos los niveles es una función fundamental en la Organización Mundial de la Salud (OMS). La evaluación de los sistemas de vigilancia epidemiológica es esencial para asegurar que los problemas de importancia para la salud pública sean monitorizados de manera eficiente y efectiva. El Sistema de Información Nutricional sobre Vitaminas y Minerales (VMNIS, por sus siglas en inglés) se evaluó desde la perspectiva de sistema de vigilancia e informática en salud pública. Los pasos incluyeron: el involucramiento de las partes interesadas en la evaluación, la descripción del sistema de vigilancia, el enfoque del diseño para la evaluación, la recopilación de pruebas fiables sobre el rendimiento del sistema, la justificación y desarrollo de conclusiones y recomendaciones, y la diseminación de las lecciones aprendidas de la evaluación. Después de este proceso, la OMS inició importantes esfuerzos para mejorar y ampliar el Sistema de Información Nutricional sobre Vitaminas y Minerales para lograr una base de datos más flexible y eficiente. Este artículo resume la evaluación de esta base de datos para documentar un buen ejemplo de cómo los marcos de evaluación en salud pública pueden llevar a mejorar la información en los sistemas de vigilancia contribuyendo de esta manera al objetivo final de mejorar la salud pública.

La generalización entre contextos como función del entrenamiento en una tarea instrumental con humanos / Generalization among Contexts as a Function of Training Humans in an Instrumental Task

León, Abad y Rosas, (2010b) demostraron que la atención al contexto se pierde conforme aumenta el entrenamiento. Así, a medida que aumenta el entrenamiento se observa una mayor generalización entre contextos distintos al de entrenamiento al perderse la atención. El objetivo del presente estudio fue poner a prueba ésta idea empleando una tarea instrumental en humanos con distintos valores del contexto (color). La tarea consistió en un juego de ordenador en el que se emitían distintas respuestas bajo un programa IV2s, en presencia de distintos estímulos discriminativos. En el Experimento 1 se entrenaron dos grupos con 3 y 8 ensayos, posteriormente se realizó un ensayo de prueba en el contexto de entrenamiento (amarillo) y en un contexto diferente (rojo). Los resultados demostraron una disminución de la ejecución con el cambio de contexto. En el Experimento 2 se entrenaron dos grupos de manera similar al Experimento 1, empleando un contexto naranja. Durante la prueba se presentaron degradaciones del color del contexto de entrenamiento con valores intermedios hacia el color amarillo y rojo. Los resultados sugieren que la atención al contexto de entrenamiento está modulada diferencialmente por la cantidad de entrenamiento en la tarea.

León, Abad and Rosas (2010b) shown that as the training increased attention to the context decreased. Thus, increasing the training might produce a greater generalization between different contexts. The main goal of the present experiments was to test this idea modifying different values of the context (i. e., colors) using an instrumental task with humans. The task was a videogame in which participants performed under an IV2s schedule in presence of different discriminative stimuli to obtain reinforces. In Experiment 1 two groups were trained with 3 or 8 trials, then a test trial was conducted in the training context (i. e., yellow) or in a different context (i. e., red). Results shown that changed the context produced a loss of performance. In Experiment 2 two groups were trained with similar parameters used in Experiment 1 but using an orange context. Test was conducted with different values of the orange (i. e., training context) toward yellow and red. The pattern of the data suggests that experience with the task modulates in different ways attention to contextual cues.

Daño miocárdico grave por leptospirosis: informe de un caso fatal en México / Severe myocardial damage caused by leptospirosis: report of a fatal case in Mexico

Chagasic cardiomyopathy is a common disease in Latin America, however similar clinical pictures exist that can be confused with this, as they give negative results to the tests that detects T. cruzi, like non Chagasic rural endemic chronic cardiopathy, highly common in Venezuela. Using histopathology techniques, "idiopathic cardiomyopathy" is frequently found as the cause of death when the etiology of this disease is not known. This paper presents the case of a man of 26-years-old who died of dilated cardiomyopathy secondary to leptospirosis. Clinically, in addition to the cardiac failure, jaundice, hyperbilirubinemia, transaminases increase, proteinuria and hematuria were present. Initially it was suspected Chagasic cardiomyopathy but the epidemiologic background and the parasitologic and serologic tests for T. cruzi gave negative results. The dark field microscopy videorecording of blood and urine samples, argentic impregnation and immunohistochemistry tests as well as haemoculture in EMJH medium were positive for L. interrogans serovar Pomona. Postmortem we confirmed the presence of leptospira in different tissues through of histopathology, argentic impregnation, indirect immunofluorescence and immunohistochemistry.

Fundamentación académica para la elaboración de un plan de estudios de medicina en México / Academic guidelines for the creation of a medical school curricula in Mexico

Los planes de estudio para la formación de médicos se encuentran en continua transformación. El presente trabajo es un ejercicio para el análisis y modificación de dichos planes. Se fundamenta en información de fuentes oficiales demográficas y de salud, encuestas de opinión de alumnos y profesores, lineamientos de organismos acreditadores, así como en el análisis de la situación de la formación de médicos en México y las tendencias internacionales en la educación médica. Se analizan demandas del contexto, el estado actual y las tendencias futuras de las disciplinas biológicas, sociomédicas y clínicas, situación de la docencia e investigación, planes de estudios afines, características actuales y tendencias de la formación profesional en el país y retos que enfrentan los planes estudio. La propuesta se basa en un currículo esencial, con congruencia horizontal y vertical, por competencias fundamentadas en problemas prioritarios de salud. Propicia el razonamiento científico, estrategias educativas centradas en el alumno y aprendizaje significativo. Incorpora tempranamente actividades clínicas, habilidades de comunicación y empleo de recursos tecnológicos. Define el perfil docente y programas de formación de profesores. Integra expertos en tecnología y pedagogía modernas. Establece mecanismos de evaluación permanente y para incentivar al personal académico y administrativo.

Medical training curricula is a constantly evolving field. The objective of the present study is to analyze the changes the field has undergone. Our sources of information include demographic and health surveys, surveys carried out with students and faculty members and medical school guidelines from prestigious teaching centers. We compared medical curricula offered in Mexico as well as international trends. We analyzed context requirements, current status and future trends in biological, sociomedical and clinical disciplines; research and teaching methods; adequate academic programs. We describe the state of affairs in medical teaching in Mexico and the challenges that academic programs are currently facing. We propose a curricula with horizontal and vertical planning according to skills and competences that focus on health problems to foster scientific reasoning. Teaching strategies that are student-focused and foster significant/long-lasting learning. We suggest the need to include early clinical activities, communication skills and training in technological resources. Finally, there is a need to define a teaching profile that is consistent with training programs, to include experts in technology and modern teaching methods in order to establish permanent monitoring mechanisms, and to offer incentives to academics and administrative personnel.

Wheat flour fortification for prevention and control of iron deficieny anemia in Latin America: issues to consider in a systematic evaluation

Iron deficiency continues to be a public health concern in many regions including Latin America. Various interventions such as routine supplementation with iron and folic acid to various target groups, fortification of staple foods such as wheat flour and corn meal, control of parasitic infections and improvement of sanitary conditions are implemented worldwide to address this micronutrient deficiency. Wheat flour fortification has been a common intervention to almost all countries in Latin America. Although this strategy has been underwav for several years, it seems critical to evaluate the program achievements in a systematic way in order to assess the intended and unintended outcomes and recommend actions for the future. The evaluation should include the assessment of dietary habits and the availability, access and consumption of new iron-fortified food products in the marketplace, and should consider the newer knowledge in food fortification science and technology. A systematic program evaluation can identify key issues affecting performance and provide recommendations that can be applied to improve program effectiveness. The CDC framework for evaluation of public health interventions can be used as a guide to lead the design and implementation of this task. A review of all the current and potential stakeholders involved is needed to renew and invigorate political commitment to food fortification as a strategy for iron deficiency prevention and control, in conjunction with other interventions. Reassessing the context of the fortification program, the country's food vehicle products market trends, understanding, possible changes in dietary habits and micronutrient consumption, and supplement usage could be done in order to better focus the program and provide useful recommendations to the stakeholders.

Single-channel response of hamster oocytes to fertilization with homologous spermatozoa

Electrophysiological events occur early after fertilization, along with changes in intracellular Ca2+ concentration. Passive electrical parameters were determined in golden hamster oocytes by whole cell patch-clamp method. In separate experiments the effect of 4-aminopyridine on resting oocytes was tested. The single-channel patch clamp configuration was employed to assess the electrical response to fertilization with homologous sperm. Structure of oocytes submitted to patch clamp was evaluated with scanning electron microscopy and found to be preserved.Oocyte diameter was 70.2 ± 2.2 µm; their resting parameters were: membrane potential 23.8 ± 0.8 mV; total membrane specific resistance 519.1 ± 94.6 Ù.cm2, and specific capacity 0.99 ± 0.03 µF.cm-2. Total membrane current was decreased by 42 % by 4-aminopyridine.Control oocytes and oocytes exposed to sperm differed in their membrane currents in response to a voltage ramp clamping membrane potential from - 100 mV to + 100 mV. In both cases, currents were largest at the most negative potentials, but sperm-exposed oocytes had larger currents. Additionally, while in controloocytes the current was inward at negative potentials but outward at positive potentials, in the presence of spermatozoa oocytes was inward within the whole voltage range tested. This latter current may represent Ca2+ en try

Seasonal variations in the heterologous binding of viscacha spermatozoa: A scanning electron microscope study

Seasonal changes in the reproductive activity of the adult male viscacha (Lagostomus maximus maximus) were investigated during the annual reproductive cycle. Assays of heterologous in vitro binding between compatible gametes were used to evaluate the ability of viscacha spermatozoa to achieve primary binding during its annual reproductive cycle. Sperm were collected by mincing cauda epididymis in HECM-3 medium and the sperm concentration and motility were evaluated. Cumulus-free and zona-free oocytes obtained from superovulated hamsters were inseminated in vitro with capacitated sperm suspensions, incubated at 37ºC, 5% CO2 for 3 h, and then processed for studies by scanning electronic microscopy. Statistical analysis was used to compare the quantitative differences. The number of spermatozoa significantly decreases during the regression period, while sperm motility was progressive speed in both periods. During the active period elevated sperm binding to cumulus-free and zona-free oocytes was observed, while the binding during the regression period decreased drastically. In both periods, oocyte microvilli covered sperm heads and tails. These results suggest that the ability of viscacha spermatozoa to participate in gamete recognition is profoundly affected. This would likely be related to different functional stages of the spermatozoa and their epididymal microenvironment during the annual reproductive cycle of viscacha.

Pancreatitis aguda, diabetes y sarcoidosis: Reporte de un caso y revisión del tema / Acute Pancreatitis, Diabetes, and Sacoidosis: Case Report and Review of the literature

Introducción: la sarcoidosis es una enfermedad granulomatosa crónica sistémica de causa desconocida. La afección pancreática es rara y aún más la asociación entre sarcoidosis, pancreatitis aguda y diabetes mellitus. Se reporta el primer caso en México. Reporte de caso: masculino de 29 años, con diagnóstico de sarcoidosis desde los 20 años y episodios intermitentes de afección articular, oftálmica, cutánea, pulmonar y en sistema nervioso central. A los 22 años se diagnostica diabetes mellitus. Ingresa con cuadro de pancreatitis aguda grave, que le causa la muerte. Discusión: la diabetes mellitus se debe a infiltración sarcoidotica del páncreas. La pancreatitis aguda se ha relacionado con el proceso inflamatorio o bien secundaria a la presencia frecuente de hipercalcemia en la sarcoidosis. El diagnóstico no es fácil. Esta forma de pancreatitis responde al manejo con esferoides.

Introduction: Sarcoidosis is a systemic, chronic, granulomatous disease of unknown cause. Pancreatic affection is rare and even more rare is the association among sarcoidosis, acute pancreatitis and diabetes mellitus. This is the first case reported in Mexico. Case report: Male 29 years. Sarcoidosis is diagnosed from the patient age of 20 years, with intermittent episodes affecting articulate, ophthalmic, cutaneous, lung and central nervous system. At 22 years of age the patient was diagnostic with diabetes mellitus. He was admitted with severe acute pancreatitis, that causes him to die. Discussion: Diabetes mellitus is due to sarcoidotic infiltration of pancreas. Acute pancreatitis has been related with inflammatory or secondary process to frequent presence of hypercalcemia in the sarcoidosis. Diagnosis is not easy. This type of pancreatitis responds to treatment with steroids.

Implantanción de marcapaso bicameral: una alternativa en el tratamiento de la miocardiopatía hipertrófica obstructiva / Permanent dual chamber pacemaker in the treatment of hypertrophic cardiomyopathy

La miocardiopatía hipertrófica obstructiva es una enfermedad caracterizada por una gran diversidad morfológica, fisiopatológica y clínica; aunque muchos pacientes permanecen estables y asintomáticos durante años, algunos presentan síntomas severos y progresivos o incluso muerte súbita. Los componentes fisiopatológicos que determinan el curso clínico de la enfermedad son fundamentalmente la disfunción diastólica, la isquemia miocárdica, las arritmias y la presencia y magnitud de la obstrucción al tracto de salida del ventrículo izquierdo. El objetivo del presente estudio fue comprobar que la implantación de un marcapaso bicameral en estos pacientes disminuye el gradiente subaórtico mediante la estimulación auriculoventricular. Material y métodos: Fueron seleccionados seis pacientes que ingresaron por lipotimia, síncope, angina e insuficiencia cardiaca clase III, así como por la presencia de un soplo mesosistólico II/IV en el foco accesorio aórtico sin irradiación. El ecocardiograma transtorácico demostró datos de hipertrofia obstructiva, con gradientes mayores a 50 mm Hg, que se confirmaron con cateterismo cardiaco; todos presentaban movimiento sistólico anterior de la valva anterior de la mitral. Se les colocó un marcapaso bicameral y se realizó estimulación auriculoventricular a partir de 140 mseg. Resultados: La estimulación auriculoventricular produjo una disminución del gradiente subaórtico en los seis pacientes a estimulaciones de 90 mseg y desapareció el movimiento sistólico anterior de la valva anterior de la mitral. Conclusión: La estimulación auriculoventricular con marcapaso bicameral disminuye el gradiente subaórtico en la miocardiopatía hipertrófica obstructiva y puede ser una alternativa de tratamiento.

Infarto agudo miocárdico inferior secundario asociado a un mixoma de la aurícula izquierda / Left atrial myxoma associated with inferior myocardial infarction

Los tumores primarios del corazón son raros, con una incidencia menor del 1 por ciento de los tumores del cuerpo. El mixoma es el más frecuente de ellos y se localizan principalmente en la aurícula izquierda. Se presenta el caso de una mujer de 57 años que ingresa al Servicio de Urgencias por un cuadro de isquemia cerebral transitoria manifestada por una hemiparesia fasciocorporal izquierda, presentando inmediatamente un infarto agudo del miocardio de localización inferior acompañado de varios eventos súbitos de edema agudo de pulmón. En la exploración física sobresale la presencia de un soplo mitral holosistólico acompañado de un primer ruido brillante. La coronariografía no mostró lesiones angiográficas significativas, tanto en la arteria coronaria derecha como en la coronaria izquierda el flujo era TIMI III. El ecocardiograma transtorácico demostró la presencia de una masa en la aurícula izquierda, la cual estaba ocupada en su totalidad y prolapsaba al ventrículo izquierdo; este hallazgo fue corroborado en la tomografía axial computarizada de tórax. La asociación de un infarto agudo del miocardio con un mixoma es una enfermedad sumamente rara y es ocasionado por la embolización coronaria o por obstrucción del tracto de salida del ventrículo izquierdo. Habitualmente, en presencia de mixoma de localización izquierda, el sitio hacia donde más frecuentemente embolizan es el sistema nerviosos central.

El espectro morfológico del complejo esclerosis tuberosa: análisis de cuatro casos de autopsia / The morphological spectrum of the tuberous sclerosis complex: analysis of four necropsy cases

Se informan cuatro casos de esclerosis tuberosa. Los hallazgos post mortem más frecuentes fueron hamartomas subependimarios y angiofibromas faciales. También se encontraron astrocitomas subependimarios de células gigantes, rabdomiomas cardiacos múltiples, riñones poliquísticos, fibromas subungueales, manchas hipopigmentadas y angiomiolipomas renales. La presentación clínica y morfológica de la esclerosis tuberosa es variada y heterogénea y en esta breve serie se revisan los aspectos patológicos más importantes para su diagnóstico.

Aterectomía coronaria por rotaablación en un caso de alto riesgo / Rotational coronary atherectomy in a high risk case

La angioplastia coronaria percutánea es el método utilizado con mayor frecuencia en las últimas décadas en el tratamiento de la enfermedad coronaria. Su éxito en pacientes mayores de 70 años está en relación con lo complejo y calcificado de la lesión. La aterectomía por rotaablación incrementa el éxito en este tipo de lesiones. Presentamos el caso de un hombre de 82 años de edad con una lesión de la arteria coronaria izquierda descendente anterior, en su tercio medio, calcificada y compleja, en el que la angioplastia coronaria percutánea fue fallida y ocasionó una disección en el sitio de la lesión. Ésta es una de las contraindicaciones que se estipulan para la rotaablación, la cual fue exitosa, permitiendo realizarle la angioplastia coronaria percutánea, así como la colocación de un stent en la lesión. Consideramos que los factores fundamentales para el éxito del procedimiento fueron tanto el diámetro del vaso como el flujo coronario.

Miopatía hipetiroidea. Presentación de un caso de curso clínico subagudo / Hyperthyroid myopathy. Presentation of a case of subacute clinical evolution

Se presenta el primer caso de miopatía hipertiroidea en autopsia en el Hospital General de México. Se trata de un hombre de 33 años con enfermedad de Graves-Basedow, quien 30 días antes de su muerte presentó debilidad muscular importante de miembros pélvicos y torácicos, además de disfagia y disfonía. Murió con datos de insuficiencia respiratoria. En los exámenes de laboratorio presentó hipopotasemia. En la autopsia se encontró adelgazamiento, exoftalmos leve, bocio hiperplásico difuso, así como atrofia, infiltración grasa y vacuolación focal en los músculos. Las miopatías relacionadas con hipo e hiperfunción tiroidea son poco frecuentes y recuerdan otras alteraciones musculares primarias y secundarias