A protein kinase coordinates cycles of autophagy and glutaminolysis in invasive hyphae of the fungus Magnaporthe oryzae within rice cells.

The blast fungus Magnaporthe oryzae produces invasive hyphae in living rice cells during early infection, separated from the host cytoplasm by plant-derived interfacial membranes. However, the mechanisms underpinning this intracellular biotrophic growth phase are poorly understood. Here, we show that the M. oryzae serine/threonine protein kinase Rim15 promotes biotrophic growth by coordinating cycles of autophagy and glutaminolysis in invasive hyphae. Alongside inducing autophagy, Rim15 phosphorylates NAD-dependent glutamate dehydrogenase, resulting in increased levels of α-ketoglutarate that reactivate target-of-rapamycin (TOR) kinase signaling, which inhibits autophagy. Deleting RIM15 attenuates invasive hyphal growth and triggers plant immunity; exogenous addition of α-ketoglutarate prevents these effects, while glucose addition only suppresses host defenses. Our results indicate that Rim15-dependent cycles of autophagic flux liberate α-ketoglutarate - via glutaminolysis - to reactivate TOR signaling and fuel biotrophic growth while conserving glucose for antioxidation-mediated host innate immunity suppression.

Genetic evidence for Magnaporthe oryzae vitamin B3 acquisition from rice cells.

Following penetration, the devastating rice blast fungus Magnaporthe oryzae, like some other important eukaryotic phytopathogens, grows in intimate contact with living plant cells before causing disease. Cell-to-cell growth during this biotrophic growth stage must involve nutrient acquisition, but experimental evidence for the internalization and metabolism of host-derived compounds is exceedingly sparse. This striking gap in our knowledge of the infection process undermines accurate conceptualization of the plant-fungal interaction. Here, through our general interest in Magnaporthe metabolism and with a specific focus on the signalling and redox cofactor nicotinamide adenine dinucleotide (NAD), we deleted the M. oryzae QPT1 gene encoding quinolinate phosphoribosyltransferase, catalyst of the last step in de novo NAD biosynthesis from tryptophan. We show how QPT1 is essential for axenic growth on minimal media lacking nicotinic acid (NA, an importable NAD precursor). However, Δqpt1 mutant strains were fully pathogenic, indicating de novo NAD biosynthesis is dispensable for lesion expansion following invasive hyphal growth in leaf tissue. Because overcoming the loss of de novo NAD biosynthesis in planta can only occur if importable NAD precursors (which solely comprise the NA, nicotinamide and nicotinamide riboside forms of vitamin B3) are accessible, we unexpectedly but unequivocally demonstrate that vitamin B3 can be acquired from the host and assimilated into Magnaporthe metabolism during growth in rice cells. Our results furnish a rare, experimentally determined example of host nutrient acquisition by a fungal plant pathogen and are significant in expanding our knowledge of events at the plant-fungus metabolic interface.

Metabolic constraints on Magnaporthe biotrophy: loss of de novo asparagine biosynthesis aborts invasive hyphal growth in the first infected rice cell.

The blast fungus Magnaporthe oryzae devastates global rice yields and is an emerging threat to wheat. Determining the metabolic strategies underlying M. oryzae growth in host cells could lead to the development of new plant protection approaches against blast. Here, we targeted asparagine synthetase (encoded by ASN1), which is required for the terminal step in asparagine production from aspartate and glutamine, the sole pathway to de novo asparagine biosynthesis in M. oryzae. Consequently, the Δasn1 mutant strains could not grow on minimal media without asparagine supplementation. Spores harvested from supplemented plates could form appressoria and penetrate rice leaf surfaces, but biotrophic growth was aborted and the Δasn1 strains were nonpathogenic. This work provides strong genetic evidence that de novo asparagine biosynthesis, and not acquisition from the host, is a critical and potentially exploitable metabolic strategy employed by M. oryzae in order to successfully colonize rice cells.

The Magnaporthe oryzae nitrooxidative stress response suppresses rice innate immunity during blast disease.

Understanding how microorganisms manipulate plant innate immunity and colonize host cells is a major goal of plant pathology. Here, we report that the fungal nitrooxidative stress response suppresses host defences to facilitate the growth and development of the important rice pathogen Magnaporthe oryzae in leaf cells. Nitronate monooxygenases encoded by NMO genes catalyse the oxidative denitrification of nitroalkanes. We show that the M. oryzae NMO2 gene is required for mitigating damaging lipid nitration under nitrooxidative stress conditions and, consequently, for using nitrate and nitrite as nitrogen sources. On plants, the Δnmo2 mutant strain penetrated host cuticles like wild type, but invasive hyphal growth in rice cells was restricted and elicited plant immune responses that included the formation of cellular deposits and a host reactive oxygen species burst. Development of the M. oryzae effector-secreting biotrophic interfacial complex (BIC) was misregulated in the Δnmo2 mutant. Inhibiting or quenching host reactive oxygen species suppressed rice innate immune responses and allowed the Δnmo2 mutant to grow and develop normally in infected cells. NMO2 is thus essential for mitigating nitrooxidative cellular damage and, in rice cells, maintaining redox balance to avoid triggering plant defences that impact M. oryzae growth and BIC development.

Glucose-ABL1-TOR Signaling Modulates Cell Cycle Tuning to Control Terminal Appressorial Cell Differentiation.

The conserved target of rapamycin (TOR) pathway integrates growth and development with available nutrients, but how cellular glucose controls TOR function and signaling is poorly understood. Here, we provide functional evidence from the devastating rice blast fungus Magnaporthe oryzae that glucose can mediate TOR activity via the product of a novel carbon-responsive gene, ABL1, in order to tune cell cycle progression during infection-related development. Under nutrient-free conditions, wild type (WT) M. oryzae strains form terminal plant-infecting cells (appressoria) at the tips of germ tubes emerging from three-celled spores (conidia). WT appressorial development is accompanied by one round of mitosis followed by autophagic cell death of the conidium. In contrast, Δabl1 mutant strains undergo multiple rounds of accelerated mitosis in elongated germ tubes, produce few appressoria, and are abolished for autophagy. Treating WT spores with glucose or 2-deoxyglucose phenocopied Δabl1. Inactivating TOR in Δabl1 mutants or glucose-treated WT strains restored appressorium formation by promoting mitotic arrest at G1/G0 via an appressorium- and autophagy-inducing cell cycle delay at G2/M. Collectively, this work uncovers a novel glucose-ABL1-TOR signaling axis and shows it engages two metabolic checkpoints in order to modulate cell cycle tuning and mediate terminal appressorial cell differentiation. We thus provide new molecular insights into TOR regulation and cell development in response to glucose.

Diagnóstico de la satisfacción laboral en una entidad asistencial hospitalaria / Diagnosis of job satisfaction in a hospital assistance service

Introducción: En la actualidad, las organizaciones reconocen al recurso humano como el activo más importante de las mismas, pues contribuye en el aseguramiento de los resultados y representa una ventaja competitiva, de ahí la necesidad de contar con trabajadores cada vez más satisfechos. El sector de la salud se ha planteado la necesidad de elevar los niveles de satisfacción de sus trabajadores.Objetivo: Diagnosticar la satisfacción laboral en una entidad asistencial hospitalaria. Métodos: Estudio cuasi experimental. La muestra estuvo compuesta por 301 trabajadores que se encuentran vinculados directamente a los servicios de atención de salud en el hospital. Se empleó una metodología, en la cual se integra la utilización de la encuesta para el diagnóstico de la satisfacción laboral, la observación directa ylas entrevistas individuales y grupales para profundizar en los resultados. En el estudio se incluyeron el análisis por servicios y categorías ocupacionales. Resultados: El índice de satisfacción laboral resultante del diagnóstico fue de 74,39 por ciento; las condiciones de trabajo y la estimulación moral y material fueron las dimensiones que más influenciaron en este resultado. En la evaluación por servicios solo 14 adquirieron los valores deseados, y la categoría de enfermeras resultó la más afectada. Conclusiones: La entidad asistencial hospitalaria presenta niveles no muy favorables de satisfacción laboral. A partir del análisis de las causas que generan los niveles de insatisfacción en los trabajadores, se derivó una estrategia para el progresivo mejoramiento de la organización(AU)

Introduction: The organizations recognize human resources as their most important asset because they contribute to consolidate the results and represent a competitive edge, hence the need of having increasingly satisfied workers at work posts. The health sector has set to increase the levels of job satisfaction among its workers. Objective: To diagnose job satisfaction at a hospital assistance service. Methods: A quasi-experimental study was made. The sample consisted of 301 workers who were directly linked to health care services at the hospital. The methodology combined use of surveys to diagnose job satisfaction, direct observation, individual and group interviews to delve into the results. The study included analyses by service and by occupational category. to hospital assistance services were diagnosed.Results: The results of the diagnosis proved that the highest incidence variables in hospital were those associated to moral and material incentives, working conditions and working/rest system. Nursing reached the lowest scoring in the job satisfaction diagnosis. These results gave rise to a strategy aimed at improving the organization. Conclusions: The hospital assistance service shows job satisfaction levels which are not very positive. Based on the analysis of the causes of lack of job satisfaction, a strategy is drawn for progressive improvement of the organization(AU)

Diagnóstico de la satisfacción laboral en una entidad asistencial hospitalaria / Diagnosis of job satisfaction in a hospital assistance service

Introducción: En la actualidad, las organizaciones reconocen al recurso humano como el activo más importante de las mismas, pues contribuye en el aseguramiento de los resultados y representa una ventaja competitiva, de ahí la necesidad de contar con trabajadores cada vez más satisfechos. El sector de la salud se ha planteado la necesidad de elevar los niveles de satisfacción de sus trabajadores. Objetivo: Diagnosticar la satisfacción laboral en una entidad asistencial hospitalaria. Métodos: Estudio cuasi experimental. La muestra estuvo compuesta por 301 trabajadores que se encuentran vinculados directamente a los servicios de atención de salud en el hospital. Se empleó una metodología, en la cual se integra la utilización de la encuesta para el diagnóstico de la satisfacción laboral, la observación directa ylas entrevistas individuales y grupales para profundizar en los resultados. En el estudio se incluyeron el análisis por servicios y categorías ocupacionales. Resultados: El índice de satisfacción laboral resultante del diagnóstico fue de 74,39 por ciento; las condiciones de trabajo y la estimulación moral y material fueron las dimensiones que más influenciaron en este resultado. En la evaluación por servicios solo 14 adquirieron los valores deseados, y la categoría de enfermeras resultó la más afectada. Conclusiones: La entidad asistencial hospitalaria presenta niveles no muy favorables de satisfacción laboral. A partir del análisis de las causas que generan los niveles de insatisfacción en los trabajadores, se derivó una estrategia para el progresivo mejoramiento de la organización(AU)

Introduction: The organizations recognize human resources as their most important asset because they contribute to consolidate the results and represent a competitive edge, hence the need of having increasingly satisfied workers at work posts. The health sector has set to increase the levels of job satisfaction among its workers. Objective: To diagnose job satisfaction at a hospital assistance service. Methods: A quasi-experimental study was made. The sample consisted of 301 workers who were directly linked to health care services at the hospital. The methodology combined use of surveys to diagnose job satisfaction, direct observation, individual and group interviews to delve into the results. The study included analyses by service and by occupational category. to hospital assistance services were diagnosed. Results: The results of the diagnosis proved that the highest incidence variables in hospital were those associated to moral and material incentives, working conditions and working/rest system. Nursing reached the lowest scoring in the job satisfaction diagnosis. These results gave rise to a strategy aimed at improving the organization. Conclusions: The hospital assistance service shows job satisfaction levels which are not very positive. Based on the analysis of the causes of lack of job satisfaction, a strategy is drawn for progressive improvement of the organization(AU)

GATA-Dependent Glutaminolysis Drives Appressorium Formation in Magnaporthe oryzae by Suppressing TOR Inhibition of cAMP/PKA Signaling.

Fungal plant pathogens are persistent and global food security threats. To invade their hosts they often form highly specialized infection structures, known as appressoria. The cAMP/ PKA- and MAP kinase-signaling cascades have been functionally delineated as positive-acting pathways required for appressorium development. Negative-acting regulatory pathways that block appressorial development are not known. Here, we present the first detailed evidence that the conserved Target of Rapamycin (TOR) signaling pathway is a powerful inhibitor of appressorium formation by the rice blast fungus Magnaporthe oryzae. We determined TOR signaling was activated in an M. oryzae mutant strain lacking a functional copy of the GATA transcription factor-encoding gene ASD4. Δasd4 mutant strains could not form appressoria and expressed GLN1, a glutamine synthetase-encoding orthologue silenced in wild type. Inappropriate expression of GLN1 increased the intracellular steady-state levels of glutamine in Δasd4 mutant strains during axenic growth when compared to wild type. Deleting GLN1 lowered glutamine levels and promoted appressorium formation by Δasd4 strains. Furthermore, glutamine is an agonist of TOR. Treating Δasd4 mutant strains with the specific TOR kinase inhibitor rapamycin restored appressorium development. Rapamycin was also shown to induce appressorium formation by wild type and Δcpka mutant strains on non-inductive hydrophilic surfaces but had no effect on the MAP kinase mutant Δpmk1. When taken together, we implicate Asd4 in regulating intracellular glutamine levels in order to modulate TOR inhibition of appressorium formation downstream of cPKA. This study thus provides novel insight into the metabolic mechanisms that underpin the highly regulated process of appressorium development.

Evidence for a transketolase-mediated metabolic checkpoint governing biotrophic growth in rice cells by the blast fungus Magnaporthe oryzae.

The blast fungus Magnaporthe oryzae threatens global food security through the widespread destruction of cultivated rice. Foliar infection requires a specialized cell called an appressorium that generates turgor to force a thin penetration hypha through the rice cuticle and into the underlying epidermal cells, where the fungus grows for the first days of infection as a symptomless biotroph. Understanding what controls biotrophic growth could open new avenues for developing sustainable blast intervention programs. Here, using molecular genetics and live-cell imaging, we dismantled M. oryzae glucose-metabolizing pathways to reveal that the transketolase enzyme, encoded by TKL1, plays an essential role in facilitating host colonization during rice blast disease. In the absence of transketolase, Δtkl1 mutant strains formed functional appressoria that penetrated rice cuticles successfully and developed invasive hyphae (IH) in rice cells from primary hyphae. However, Δtkl1 could not undertake sustained biotrophic growth or cell-to-cell movement. Transcript data and observations using fluorescently labeled histone H1:RFP fusion proteins indicated Δtkl1 mutant strains were alive in host cells but were delayed in mitosis. Mitotic delay could be reversed and IH growth restored by the addition of exogenous ATP, a metabolite depleted in Δtkl1 mutant strains. We show that ATP might act via the TOR signaling pathway, and TOR is likely a downstream target of activation for TKL1. TKL1 is also involved in controlling the migration of appressorial nuclei into primary hyphae in host cells. When taken together, our results indicate transketolase has a novel role in mediating--via ATP and TOR signaling--an in planta-specific metabolic checkpoint that controls nuclear migration from appressoria into primary hyphae, prevents mitotic delay in early IH and promotes biotrophic growth. This work thus provides new information about the metabolic strategies employed by M. oryzae to enable rice cell colonization.

Plant defence suppression is mediated by a fungal sirtuin during rice infection by Magnaporthe oryzae.

Crop destruction by the hemibiotrophic rice pathogen Magnaporthe oryzae requires plant defence suppression to facilitate extensive biotrophic growth in host cells before the onset of necrosis. How this is achieved at the genetic level is not well understood. Here, we report that a M. oryzae sirtuin, MoSir2, plays an essential role in rice defence suppression and colonization by controlling superoxide dismutase (SOD) gene expression. Loss of MoSir2 function in Δsir2 strains did not affect appressorial function, but biotrophic growth in rice cells was attenuated. Compared to wild type, Δsir2 strains failed to neutralize plant-derived reactive oxygen species (ROS) and elicited robust defence responses in rice epidermal cells that included elevated pathogenesis-related gene expression and granular depositions. Deletion of a SOD-encoding gene under MoSir2 control generated Δsod1 deletion strains that mimicked Δsir2 for impaired rice defence suppression, confirming SOD activity as a downstream output of MoSir2. In addition, comparative protein acetylation studies and forward genetic analyses identified a JmjC domain-containing protein as a likely target of MoSir2, and a Δsir2 Δjmjc double mutant was restored for MoSOD1 expression and defence suppression in rice epidermal cells. Together, this work reveals MoSir2 and MoJmjC as novel regulators of early rice cell infection.

Mechanisms of nutrient acquisition and utilization during fungal infections of leaves.

Foliar fungal pathogens challenge global food security, but how they optimize growth and development during infection is understudied. Despite adopting several lifestyles to facilitate nutrient acquisition from colonized cells, little is known about the genetic underpinnings governing pathogen adaption to host-derived nutrients. Homologs of common global and pathway-specific gene regulatory elements are likely to be involved, but their contribution to pathogenicity, and how they are connected to broader genetic networks, is largely unspecified. Here, we focus on carbon and nitrogen metabolism in foliar pathogens and consider what is known, and what is not known, about fungal exploitation of host nutrient and ask how common metabolic regulators have been co-opted to the plant-pathogenic lifestyle as well as how nutrients are utilized to drive infection.

Experiencia en el manejo quirúrgico del prolapso rectal mediante sutura helicoidal y anoplastia: estancia hospitalaria breve / Rectal prolapse: surgical experience with helicoidal suture and anoplasty: short hospital stay

BACKGROUND: We undertook this study to describe and analyze our experience with rectal prolapse treated by helicoidal suture and anoplasty at the Colorectal Service, Centro Médico Nacional, Adolfo Ruiz Cortines, Veracruz, México. METHODS: An ambispective study from 1999 to 2006 was performed in patients with rectal prolapse by chart review and outpatient clinic visit. All patients underwent helicoidal suture and anoplasty. RESULTS: Thirty two patients underwent surgery (12 males and 20 females). The mean age was 61.3 +/- 20.88 years (range: 21-94 years). History of rectal prolapse was from 1 month to 48 years. The most common symptoms were anal mass sensation, fecal incontinence, mucous discharge, rectal bleeding, chronic constipation and pain. Nineteen patients had a significant prior medical history and past surgical history. In-hospital stay was <24 h in 62.5% of procedures. There were no surgical complications. Two recurrences were documented and 28 patients had a minimum 12-month follow-up. To date, we have not documented any counter-referrals regarding complications or recurrences from primary care physicians. CONCLUSIONS: Helicoidal suture and anoplasty is an effective technique in rectal prolapse patients that offers certain advantages such as shorter in-hospital, rapid postoperative recovery, less surgical time and low recurrence rate.

[The burnout syndrome in medical residents working long periods]. / Síndrome de burnout en residentes con jornadas laborales prolongadas.

OBJECTIVE: to evaluate the burnout syndrome in medical residents with working periods longer than 80 hours per week. METHODOLOGY: an analytical cross-sectional study was conducted with medical residents working at Instituto Mexicano del Seguro Social hospital in Veracruz, México. The residents were classified in two groups. One group working for > or = 80 h per week (study group, SG) and another group working < 80 h per week (comparison group, CG) were studied. Participants were selected by simple random sampling. The clinical evaluation instrument was the scale of Maslach burnout inventory. RESULTS: 143 medical residents were included in the sample (SG n = 72, CG n = 71); the average age was 29.6 +/- 2.5 years, 65 % were males and 51 % were unmarried. Their length of service was 2.2 +/- 0.7 years. The mean working time was 100.5 +/- 7.2 hours per week for the SG and 64.4 +/- 9.3 hours for the CG. Burnout syndrome was present in 46 (63.8 %) medical residents with long workdays (p = 0.002); it was observed more frequently in those residents that were on call 3 times per week (p = 0.002) and among surgery residents (p = 0.035). CONCLUSION: working periods longer than 80 h per week are related to the appearance of burnout syndrome.

[Rectal prolapse. Surgical experience with helicoidal suture and anoplasty: short hospital stay]. / Experiencia en el manejo quirúrgico del prolapso rectal mediante sutura helicoidal y anoplastia: estancia hospitalaria breve.

BACKGROUND: We undertook this study to describe and analyze our experience with rectal prolapse treated by helicoidal suture and anoplasty at the Colorectal Service, Centro Médico Nacional, Adolfo Ruiz Cortines, Veracruz, México. METHODS: An ambispective study from 1999 to 2006 was performed in patients with rectal prolapse by chart review and outpatient clinic visit. All patients underwent helicoidal suture and anoplasty. RESULTS: Thirty two patients underwent surgery (12 males and 20 females). The mean age was 61.3 +/- 20.88 years (range: 21-94 years). History of rectal prolapse was from 1 month to 48 years. The most common symptoms were anal mass sensation, fecal incontinence, mucous discharge, rectal bleeding, chronic constipation and pain. Nineteen patients had a significant prior medical history and past surgical history. In-hospital stay was <24 h in 62.5% of procedures. There were no surgical complications. Two recurrences were documented and 28 patients had a minimum 12-month follow-up. To date, we have not documented any counter-referrals regarding complications or recurrences from primary care physicians. CONCLUSIONS: Helicoidal suture and anoplasty is an effective technique in rectal prolapse patients that offers certain advantages such as shorter in-hospital, rapid postoperative recovery, less surgical time and low recurrence rate.

[Exactness of transcutaneous sonography in the diagnosis of gastric wall lesions]. / Exactitud de la sonografía transcutánea en el diagnóstico de lesiones de pared gástrica.

OBJECTIVE: Our objective was to determine sensitivity, especificity and predictive values of transcutaneous sonography for detecting gastric wall lesions. MATERIALS AND METHODS: This prospective study was performed from March 1999 to April 2000 on 150 patients referred for transcutaneous sonography by the Endoscopic Service Unit. Sonographic examinations were performed using RT 4000 General Electric equipment with 5 Mhz transducer and replenishment of stomach with fluid. All scanning was done by the same sonographer, who was unaware of endoscopic, tomographic, or upper gastrointestinal series features. Results from sonography were compared with gastrointestinal tract endoscopy. Sensitivity, specificity, and predictive values were determined using contingency statistical procedure. Sonographic examination accuracy was calculated evaluating sensitivity and specificity confidence intervals (CI). Kappa index was calculated. Diagnostic accuracy differences observed between tumoral and non-tumoral lesions by sonography were evaluated by chi 2 probe. RESULTS: Sensitivity of 85% (95% CI, from 75.2 to 94.8%) and specificity of 90% (95% CI, from 86 to 93.9%) were obtained. Positive predictability was 78% and negative predictability was 94%. Diagnostic accuracy was 87%. Kappa index was 0.717. There were 35 no false-positive results (19 tumoral lesions and 16 non-tumoral lesions), seven false-negative results (one tumoral lesion and six non-tumoral lesions) and 10 false-positive results (two tumoral lesions and eight non-tumoral lesions). Only one of 20 tumoral lesions were diagnosed by ultrasound whereas from 22 non-tumoral lesions were not diagnosed 6 (chi 2 = 3.74, p > 0.05). CONCLUSION: Transcutaneous sonography is a rapid, low cost and non-invasive method that may be useful to establish clinic diagnosis and in the first steps of gastric wall lesions evaluation, it is valuable in assessment of diagnostic orientation for the referring clinic.

Resultados de la corrección del prolapso rectal con la técnica de fijación al promontorio del sacro / Results of rectal prolapse with fixation to the promontory

Introducción: proponer una alternativa de tratamiento quirúrgico con la técnica de Roscoe, Graham y Ripstein modificada, y determinar su eficacia para el prolapso rectal.Material y método: se presenta la experiencia de 10 años (1990-1999) de una serie de casos de pacientes con prolapso rectal completo, diagnosticados tanto clínicamente como por radiodiagnóstico y endoscopia, los cuales fueron sometidos a cirugía, con la técnica de fijación del recto al promontorio, en el Hospital de Especialidades del Centro Médico Nacional "Adolfo Ruiz Cortínes" del Instituto Mexicano del Seguro Social en la ciudad de Veracruz. Los datos fueron tomados directamente del paciente y de su expediente clínico. El análisis de los resultados se realizó con metodología de estadística descriptiva.Resultados: se estudiaron 58 casos, 67.24 por ciento correspondió al sexo masculino y 32.76 por ciento al femenino, con una proporción de 3:1. La edad promedio del grupo fue de 49.5 años y el tiempo promedio de evolución de los síntomas fue de 5.3 años. El seguimiento clínico postoperatorio fue de 2 a 10 años. La evolución fue satisfactoria en 98.28 por ciento, existiendo solamente recidiva del prolapso en 1.72 por ciento de los casos. La mortalidad fue de cero. La morbilidad de 3.74 por ciento, con un absceso de pared en un caso y en otro paciente impotencia sexual, que se resolvió mediante la colocación de prótesis peneana.Discusión: la técnica propuesta se considera una alternativa en el tratamiento quirúrgico del prolapso rectal, con reducción permanente de este último en la mayoría de los casos operados (eficacia de 92.28 por ciento), además de ser una técnica sencilla de realizar.

Exactitud de la biopsia por aspiración con aguja fina en el diagnóstico de nódulos tiroideos / Fine needle aspiration accuracy for thyroid nodules diagnosis

Objetivo. Determinar la exactitud de la BAAF en el diagnóstico de nódulos tiroideos. Diseño del estudio: Prueba diagnóstica. Métodos. Se realizó estudio prospectivo de febrero a octubre de 1998 y se incluyeron pacientes adultos, de cada sexo, a los que se les realizó biopsia por aspiración con aguja fina y cirugía de nódulos tiroideos; para cada procedimiento se firmó consentimiento informado; el proyecto fue aprobado por el comité local de investigación. Las muestras las analizó un patólogo experto en citología. El resultado de ambos estudios se comparó en cuanto a resultados positivos y negativos para cáncer de tiroides, y se analizó su sensibilidad, especificidad, exactitud diagnóstica, valor predictivo positivo y negativo. Resultados. Se estudió un total de 65 pacientes, 48 mujeres y 17 hombres, todos con nódulos tiroideos, hubo 29 pacientes con cáncer de tiroides y 36 sin él. La sensibilidad fue de 76 por ciento, especificidad 100 por ciento, exactitud 89.23 por ciento, valor predictivo positivo 83.72 por ciento y valor predictivo negativo 100 por ciento. Conclusiones. La BAAF tiene una buena exactitud diagnóstica (89 por ciento) y es más útil para descartar pacientes a quienes se sometieron a tratamiento quirúrgico

Aprendizaje en la residencia de cirugía / Learning at surgical education

Hipótesis. El avance técnico en la cirugía no va a la par con el avance en la técnica usada para su aprendizaje, por lo que algunos aspectos didácticos requieren ser analizados y reconsiderados. Objetivo. Analizar el proceso de aprendizaje en la residencia de cirugía. Método. Estudio prospectivo, octubre de 1996, encuesta anónima a médicos y residentes de cirugía general; 11 preguntas cerradas y 12 abiertas, análisis con estadística descriptiva y por categorías. Resultados. Se estudió 15 residentes (100 por ciento), cinco R2, cuatro R3 y seis R4, sexo masculino, edad 26 a 41 años, moda 28. Principales problemas durante la residencia: económico y falta de tiempo libre para estudiar y estar con la familiar. Factores que favorecen su aprendizaje: apoyo de los maestros, la cantidad de casos que atienden, la biblioteca, las clases. Factores que dificultan su aprendizaje: exceso de trabajo, falta de tiempo libre para descanso y estudio, medio hostil, falta de bibliografía disponible. Propuestas de soluciones: mayor organización de grupo, estudiar más, mejor organización integral del tiempo. Conclusiones. El aprendizaje en la residencia de cirugía se da principalmente a base de la enseñanza tutelar y la práctica clínica-quirúrgica; adolece de exceso de trabajo que resta tiempo para el descanso, el estudio y la vida familiar