Entrenamiento procedimental básico (EPROBA) en suturas para estudiantes de medicina durante pandemia por SARS-CoV-2 (COVID-19) / Suturing basic procedural skills training for medical students during COVID-19 pandemic

BACKGROUND: The adoption of sanitary measures due to the SARS-CoV-2 pandemic hampered teaching and learning methods in medicine. AIM: To communicate the results of a wound suture training workshop, based on the Basic Procedural Skills Training methodology and adapted to the pandemic context. MATERIAL AND METHODS: One hundred fourteen students were randomized in small groups due to sanitary measures and trained with a modification of the Basic Procedural Skills Training methodology. An informed consent was obtained from every student. The suturing skills were evaluated before and after the intervention with "The Objective Structured Assessment Of Technical Skills" (OSATS) instrument. The perception of the workshop and the implementation of the COVID-19 prevention measures were also evaluated. RESULTS: The students showed a statistically significant improvement after the intervention. In the OSATS verification list, the average score increased from 4.5 to 8.6 (p < 0.01). In the OSATS global scale, the average score increased from 13.0 to 25.3 (p < 0.01). The perception of the workshop and the prevention measures were well evaluated. CONCLUSIONS: Despite all the limitations of the pandemic context, we achieved a significant improvement after the intervention and a very good perception by the students.

[Suturing basic procedural skills training for medical students during COVID-19 pandemic]. / Entrenamiento procedimental básico (EPROBA) en suturas para estudiantes de medicina durante pandemia por SARS-CoV-2 (COVID-19).

BACKGROUND: The adoption of sanitary measures due to the SARS-CoV-2 pandemic hampered teaching and learning methods in medicine. AIM: To communicate the results of a wound suture training workshop, based on the Basic Procedural Skills Training methodology and adapted to the pandemic context. MATERIAL AND METHODS: One hundred fourteen students were randomized in small groups due to sanitary measures and trained with a modification of the Basic Procedural Skills Training methodology. An informed consent was obtained from every student. The suturing skills were evaluated before and after the intervention with "The Objective Structured Assessment Of Technical Skills" (OSATS) instrument. The perception of the workshop and the implementation of the COVID-19 prevention measures were also evaluated. RESULTS: The students showed a statistically significant improvement after the intervention. In the OSATS verification list, the average score increased from 4.5 to 8.6 (p < 0.01). In the OSATS global scale, the average score increased from 13.0 to 25.3 (p < 0.01). The perception of the workshop and the prevention measures were well evaluated. CONCLUSIONS: Despite all the limitations of the pandemic context, we achieved a significant improvement after the intervention and a very good perception by the students.

Rol de conocimientos previos en los resultados de un programa de entrenamiento en sutura de heridas para estudiantes de medicina mediante metodología EPROBA / Role of previous knowledge in the results of a training program in wound suturing for medical students using EPROBA methodology

Resumen Objetivo: Comparar la adquisición de habilidades quirúrgicas básicas en estudiantes de medicina según el tipo de instrucción teórico-práctica recibida previo a un taller estandarizado de sutura de heridas. Materiales y Método: Estudio cuasiexperimental antes-después para estudiantes de cuarto año durante el 2018. Se realizó taller de sutura de heridas aplicado en modelo biológico (pata de cerdo), previo consentimiento informado y aprobación Comité Ético Científico. Mediante instrumento "The Objective Structured Assessment Of Technical Skills" (OSATS) se evaluó técnica de sutura antes y después del entrenamiento. Se dividió a los participantes según conocimientos previos al taller: Grupo A: recibió instrucción teórico-práctica en pacientes in vivo. Grupo B: recibió instrucción teórico-práctica en modelos de simulación. Grupo C: sin conocimientos previos en suturas. Se evaluó percepción de estudiantes mediante encuesta validada. Se comparó puntaje OSATS antes-después del taller y encuesta de percepción según grupo, utilizando SPSS24® y ANOVA. Se consideró significativo p < 0,05. Resultados: Se evaluaron 124 estudiantes. Grupo A: 17 (13,7%); Grupo B: 38 (30,7%); Grupo C: 69 (55,6%) respectivamente. Existió diferencia en puntaje OSATS de ingreso al taller Grupo A: 19,4 ± 4,9; Grupo B: 13,7 ± 6,3; Grupo C: 11,1 ± 4,5 (p < 0,05). Puntaje OSATS finalizada la intervención Grupo A: 28,8 ± 1,5; Grupo B: 28,0 ± 1,9; Grupo C: 27,9 ± 2,2 (p = 0,48), sin diferencia significativa. La intervención fue bien percibida, sin diferencias significativas entre grupos. Discusión: El resultado de evaluación OSATS finalizado el taller es independiente de experiencias, instrucción teórico-práctica o conocimientos previos a la intervención. Conclusión: Los programas de entrenamiento con evaluación estandarizada pueden equiparar los resultados entre estudiantes con diferentes conocimientos previos.

Aim: To compare the learning of basic surgical skills among medical students according to the type of theoretical and practical instruction they had prior to a standardized wound suturing workshop. Materials and Method: Quasi-experimental before and after study intended to fourth year students for the 2018. The wound suturing workshop was carried out with help of a biological model (pork leg), prior to an informed consent and the approval of the Ethics Committee. The suturing skills were evaluated by the tool "The Objective Structured Assessment Of Technical Skills" (OSATS) before and after the training. All of the participating students were sorted in groups by their previous surgical knowledge: Group A: received theoretical and practical instruction in patients. Group B: received theoretical and practical instruction in simulation models. Group C: without previous suturing knowledge. The students perception was evaluated by a validated survey. The OSATS score before and after the workshop and the perception survey were compared between the groups, using SPSS24® and ANOVA. p < 0,05 was considered significant. Results: 124 students were evaluated. Group A: 17 (13.7%); Group B: 38 (30.7%); Group C: 69 (55.6%) accordingly. There was a OSATS score difference before the workshop Group A: 19.4 ± 4,9; Group B: 13.7 ± 6.3; Group C: 11.1 ± 4.5 (p < 0.05). OSATS score after the intervention Group A: 28.8 ± 1.5; Group B: 28.0 ± 1.9; Group C: 27.9 ± 2.2 (p = 0.48), without a significant difference. The intervention was well perceived, without significant differences among the groups. Discussion: The OSATS score post workshop is independent of experiences, theoretical and practical instruction or previous knowledge. Conclusion: Training programs with standardized evaluation can even out the results among students with different previous knowledge.

Entrenamiento de competencias procedimentales quirúrgicas básicas en estudiantes de Medicina mediante un modelo de simulación (EPROBA) / Training of basic surgical procedural skills in medical students using a simulation model (EPROBA)

Resumen Introducción: Los modelos de simulación otorgan entornos controlados para la práctica y la retroalimentación por parte de un tutor. Frente a una primera experiencia, nuestro grupo implementó un modelo simplificado y reproducible para el entrenamiento de habilidades quirúrgicas básicas. Objetivo: Comunicar los resultados de un taller de entrenamiento basado en simulación para la adquisición de habilidades quirúrgicas básicas en estudiantes de Medicina. Materiales y Método: Estudio cuasiexperimental, antes y después, 124 estudiantes de medicina de cuarto año fueron entrenados con la metodología EPROBA (Entrenamiento Procedimental Básico), previo consentimiento informado. Mediante el instrumento "The Objective StructuredAssessment Of Technical Skills" (OSATS) se evaluó la técnica de sutura previo y posterior a la intervención. Se evaluó la percepción de los estudiantes mediante una encuesta validada. Para el análisis estadístico se utilizó SPSS24® y se usó la prueba Mann Whitney para variables no paramétricas considerando significativo p < 0,05. Resultados: El grupo muestra un progreso promedio significativo en su desempeño procedimental. En la Lista de Comprobación OSATS muestra un progreso desde 4,1 puntos a 8,9 (p < 0,001). En la Escala Global OSATS muestra un puntaje basal de 13,0 puntos, aumentando a 28,0 puntos (p < 0,001). La intervención fue bien percibida, obteniendo un puntaje total promedio de 65,4 puntos de 68 máximos. Conclusión: En nuestra experiencia, un modelo simplificado demostró ser eficaz para el entrenamiento en habilidades procedimentales simples como suturas. Múltiples instancias de práctica deben ser otorgadas por las Facultades de Medicina para la retención y mejora de estas habilidades.

Background: Simulation models provide controlled environments for the practice and tutor feedback. Faced with a first experience, our group implemented a simplified and reproducible model for the training of basic surgical skills. Aim: Communicate the results of a training workshop based on simulation for the basic surgical skills training in medical students. Materials and Method: Quasi-experimental study, before and after, 124 fourth year medical students were trained with "EPROBA" methodology, with prior informed consent. Through the instrument "The Objective Structured Assessment of Technical Skills" (OSATS) the technique of suture before and after the intervention was evaluated. The perception of the students was evaluated through a validated survey. For statistical analysis SPSS24® was used and the Mann Whitney test was used for nonparametric variables, it was considered significant p < 0.05. Results: The group shows a significant average progress in its procedural performance. In the OSATS Checklist they show a progress from 4.1 points to 8.9 after the intervention (p < 0.001). In the OSATS Global Scale they show a baseline score of 13.0 points, rising to 28.0 points (p < 0.001). The intervention was well perceived, obtaining a total average score of 65.4 points of 68 maximums. Conclusión: In our experience, a simplified model proved to be effective for training in simple procedural skills such as sutures. Multiple instances of practice must be granted by the Faculties of Medicine for the retention and improvement of these skills.

Mastectomía subcutánea con reconstrucción inmediata del complejo areolomamilar en transexuales masculinos / Subcutaneous mastectomyy, with immediate reconstruction of the areolo-mamilar complex in male transexuals

Resumen Objetivo: Se presenta experiencia realizada en Servicio de Salud Talcahuano, de masculinización mamaria en el proceso de reasignación sexual, de transexuales masculinos. En Chile se estima que habrían 754 mujeres transexuales. Materiales y Método: Estudio de 47 individuos, intervenidos en Hospital Las Higueras de Talcahuano, entre 2006 y 2019, sometidos a masculinización mamaria mediante mastectomía subcutánea y reconstrucción del complejo areolomamilar. Resultados: Se intervinieron pacientes de todo el país; 59% corresponde a octava región; 42,5% operados entre los años 2017 y 2018. Un 36% rango de edad de 18 a 22 años. Un 68% IMC entre 24 y 30. Según el tamaño de las mamas, 57% copa B, 31% C, 12% D y 12% de gigantomastía. Un 29%, peso promedio de la mastectomía fue de 600 g; un 29% de 300 gramos y en 9% más de 800 g por lado. En 68% se utilizó abordaje submamario e injerto de piel total del complejo aréola pezón (CAP); otras tecnicas fueron periareolar, incisión en T y liposucción. La complicación más frecuente fue la colección. Biopsia normal en un 100%. Discusión: Experiencia pionera en Chile, realizada en un Hospital Público, en el difícil proceso de reasignación de género, en la población transexual de Chile. Individuos muy estigmatizados de parte de la comunidad, que encontraron en el Servicio de Salud de Talcahuano, una mano amiga, que les extendió su apoyo desinteresado y calificado, logrando excelentes resultados finales.

Aim: Describe the experience in Talcahuano Helath Service, of mammary masculinization in the sexual reassignment process, of male transsexuals. In Chile it is estimated that there will be 754 transsexual women. Materials and Method: Study of 47 individuals, operated at Las Higueras Hospital in Talcahuano, between 2006 and 2019, subjected to breast masculinization by subcutaneous mastectomy and reconstruction of the areolomamilar complex. Results: Patients from all over the country were operated; 59% corresponds to the Bio-Bio province; 42.5% operated between 2017 and 2018. A 36% range of ages from 18 to 22 years. 68% BMI between 24 and 30. According to the size of the breasts, 57% B cup, 31% C, 12% D and 12% gigantomasty. At 29%, the average weight of the mastectomy was 600 grams; 29% of 300 grams and 9% more than 800 grams per side. In 68%, the submammary approach and total skin graft of the CAP were used; Other techniques were periareolar, incision in T and liposuction. The most frequent complication was the collection. 100% normal biopsy. Discussion: Pioneering experience in Chile, carried out in a public hospital, in the difficult process of gender reassignment, in the transsexual population of Chile. Individuals very stigmatized by the community, who found in the Health Service of Talcahuano, a helping hand, which extended their selfless and qualified support, achieving excellent final results.

Retención de competencias procedimentales en estudiantes de medicina posterior a un entrenamiento mediante un modelo de simulación (EPROBA)

Background: Boot camps are used to acquire skills in simple surgical procedures, such as sutures, in a short period of time. Aim: To assess the retention of the procedural skills of medical students who participated in a simulation-based suture workshop. Material and Methods: One hundred five medical students were trained using the EPROBA methodology (Entrenamiento PROcedimental BAsico), with prior informed consent. The instrument "Objective Structured Assessment Of Technical Skills" (OSATS) was applied prior to and after the workshop, and during retention module, which was carried out between three and four months after the suture workshop. Participants were classified according to the level of previous knowledge in sutures. Results: The students showed significant improvement in their scores after the workshop (improvement from 12.9 to 28.5 points, p < 0.001). No significant differences were found between scores after the workshop and those obtained in the retention module (28.5 to 28.1 points, respectively, p = 0.235). No difference in scores were observed when retention was evaluated according to previous knowledge levels. Conclusions: Simulation programs are useful for the acquisition of procedural skills which are retained over time.

[Retention of procedural competences in medicine students after training using a simulation model]. / Retención de competencias procedimentales en estudiantes de medicina posterior a un entrenamiento mediante un modelo de simulación (EPROBA).

BACKGROUND: Boot camps are used to acquire skills in simple surgical procedures, such as sutures, in a short period of time. AIM: To assess the retention of the procedural skills of medical students who participated in a simulation-based suture workshop. MATERIAL AND METHODS: One hundred five medical students were trained using the EPROBA methodology (Entrenamiento PROcedimental BAsico), with prior informed consent. The instrument "Objective Structured Assessment Of Technical Skills" (OSATS) was applied prior to and after the workshop, and during retention module, which was carried out between three and four months after the suture workshop. Participants were classified according to the level of previous knowledge in sutures. RESULTS: The students showed significant improvement in their scores after the workshop (improvement from 12.9 to 28.5 points, p < 0.001). No significant differences were found between scores after the workshop and those obtained in the retention module (28.5 to 28.1 points, respectively, p = 0.235). No difference in scores were observed when retention was evaluated according to previous knowledge levels. CONCLUSIONS: Simulation programs are useful for the acquisition of procedural skills which are retained over time.

Tutoría por pares de distinto año académico en la enseñanza de habilidades quirúrgicas básicas en estudiantes de pregrado de medicina / Peer tutoring in the teaching of basic surgical skills in medical undergraduate students

Resumen Objetivo: Nuestro objetivo es comparar la efectividad de la tutoría impartida por pares de 6° versus 14° semestre en la adquisición de habilidades procedimentales básicas en estudiantes de medicina. Materiales y Método: Estudio cuasi-experimental, antes y después. La intervención consta inicialmente de un curso de formación de monitores de sutura (MS) para dos estudiantes de 6° y dos de 14° semestre de medicina. Posteriormente se implementó un taller de sutura tutorizado por MS a 23 estudiantes de 8° semestre de medicina. Se evaluó sutura continua y discontinua mediante el instrumento: "The Objective Structured Assessment Of Technical Skills" (OSATS) y satisfacción mediante encuesta tipo Likert validada por expertos. Se describen y comparan los resultados pre y postintervención y satisfacción de los estudiantes, de acuerdo al semestre cursado del MS. Se aplicó consentimiento informado. Se utilizó SPSS24® para análisis estadístico mediante prueba de Mann Whitney. Se consideró significativo p < 0,05. Resultados: Ambos grupos progresaron significativamente en la escala OSATS, grupo tutorizado por MS de 6° semestre: 18,1 vs 28,1 (p < 0,001) y grupo tutorizado por MS de 14° semestre: 15,5 vs 27,8 (p < 0,001). Los puntajes finales no presentan diferencias significativas. La intervención fue evaluada con 66 de 68 puntos, sin diferencias significativas según el semestre cursado del MS. Conclusión: Nuestra experiencia muestra que es posible utilizar la tutoría por pares entrenados para la enseñanza de habilidades quirúrgicas, independientemente si la tutoría es impartida por pares de cursos inferiores o superiores, logrando un progreso significativo y un desempeño procedimental equivalente, además de una alta satisfacción entre los estudiantes.

Aim: Our objective is to compare the effectiveness of tutoring taught by 6th versus 14th semester peer students in the acquisition of basic procedural skills in medical students. Materials and Method: Quasi experimental study, before and after. The intervention initially consists of a training workshop for suture monitors (SM) for two students of 6th and two students of 14th semester of medicine. Subsequently, a suture workshop taught by SM to 23 fourth-year medical students was implemented. Continuous and discontinuous suture was evaluated using the instrument: "Objective structured evaluation of technical skills" (OSATS) and satisfaction through a survey validated by experts. The results of pre and post intervention and student satisfaction are described and compared, according to the semester attended by the SM. Informed consent was applied. Excel® and SPSS24® were used for statistical analysis by Mann Whitney test. It was considered significant p < 0.05. Results: Both groups progressed significantly on the OSATS scale, group tutored by 6° semester SM: 18.1 vs 28,1 (p < 0.001) and group tutored by 14° semester SM: 15.5 vs 27,8 and (p < 0.001). The final scores did not they present significant differences. The intervention was well evaluated with 66 out of 68 points, without significant differences according to the semester coursed of the SM. Conclusion: Our experience shows that it is possible to use peer tutoring by trained tutors to teach surgical skills, regardless of whether the teaching is given by pairs of lower or higher courses, achieving significant progress and equivalent procedural performance, in addition to high satisfaction among students.

Implementación de taller de monitores de sutura en alumnos de pregrado de medicina / Implementation of suture monitor workshop in undergraduate medical students

INTRODUCCIÓN: Las técnicas de sutura básicas se consideran competencias mínimas de un egresado de medicina y son fundamentales en el ejercicio de la medicina general. Actualmente, los estudiantes de la Universidad de Concepción no poseen una instancia formal para adquirir estas competencias. OBJETIVOS: Evaluar la validez de un programa de formación de alumnos monitores de sutura a través de los resultados obtenidos mediante un método de evaluación estandarizado, realizado en estudiantes de pregrado de medicina de la Universidad de Concepción. METODOLOGÍA: Estudio preexperimental antes y después. Se realizó intervención teórico-práctica para seis estudiantes de medicina de distintos semestres cursados, entre los meses de mayo y julio de 2017. Consistió en tres módulos: clases teóricas, práctica en modelo biológico y módulo en pabellón quirúrgico supervisado por subespecialistas. Se evaluó punto de sutura continuo y discontinuo en modelo biológico mediante la escala "The Objective Structured Assessment Of Technical Skills" (OSATS). Se describen y comparan resultados de la escala OSATS antes y después del curso. Se aplicó consentimiento informado. Se utilizó SPSS® para análisis estadístico mediante prueba de Mann-Whitney para variables no paramétricas. Se consideró significativo p < 0,05. RESULTADOS: Todos los participantes mejoraron puntuación en escala OSATS. Los participantes progresaron significativamente sus resultados en las distintas escalas OSATS (5,2 vs 8,8; p < 0,05 y 16,5 vs 27,2; p < 0,05) al comparar resultados pre vs posintervención respectivamente. DISCUSIÓN: Nuestra experiencia demuestra que es posible crear un taller de formación de MS con muy buenos resultados, para estudiantes de medicina, a través de una capacitación trimodal, con clases teóricas, simulación y práctica in vivo. Además, constituye la base de futuras investigaciones que buscan solucionar la inexistencia de un programa formal de enseñanza de técnicas de sutura a los estudiantes de medicina de nuestra facultad.

INTRODUCTION: Suture techniques are considered the minimum of a medical examination and are fundamental in the practice of medicine. Currently, the students of the Universidad de Concepción do not have a formal instance to acquire these competences. AIM: To evaluate the validity of a training program for Suture Instructor (SI) students through the results obtained through a standardized assessment method, carried out in undergraduate students of medicine at the University of Concepción. METHOD: Preexperimental before and after study. A theoretical-practical intervention was carried out for six medical students of different semesters of the career, between the months of May and July 2017. It consisted of three modules: theoretical classes, practice in biological model and module in surgical pavilion supervised by subspecialists. Continuous and interrupted sutures were evaluated in the biological model using the "The Objective Structured Assessment of Technical Skills" (OSATS) scale. Results of the OSATS scale are described and compared before and after the course. Informed consent was applied. SPSS® was used for statistical analysis by Mann-Whitney test for non-parametric variables. It was considered significant p < 0.05. Results: All participants improved score on OSATS scale. The participants progressed significantly their results in the different OSATS scales (5.2 vs 8.8, p < 0.05 and 16.5 vs 27.2, p < 0.05) when comparing pre vs post intervention results respectively. DISCUSSION: Our experience shows that it is possible to create an SI training workshop with excellent results for medical students, through a three phase training program, with theory classes, simulation and "in vivo" practice. It also constitutes the basis of future research that seeks to solve the lack of a formal program of teaching suture techniques to medical students of our university.

Cobertura con colgajo escrotal en desforramiento peneano: a propósito de dos casos / Scrotal fasciocutaneous flap coverage in degloving lesión of penis, report of two cases

Restablecer la cobertura cutánea en lesiones de urgencia es un desafío para el cirujano, más aún si se trata del pene, ya sea por desforramiento accidental o secundario a procesos sépticos de la región perineal. Se presentan 2 casos. El primero por lesión accidental en un menor de 9 años, quien pierde la totalidad de la piel peneana. El segundo caso en un paciente de 65 años, diabético e hipertenso que presentó un episodio de fasceítis necrotizante. En ambos casos se realiza una cobertura cutánea del defecto utilizando 2 colgajos fasciocutßneos de las bolsas escrotales. En el caso del ni±o, el defecto de cobertura creado en éstas se cubre con colgajo fasciocutáneo de la cara anterior del muslo, y éste último con un injerto dermoepidérmico de la extremidad contralateral, utilizando la misma técnica descrita para el menor. La técnica utilizada cumplió plenamente con los objetivos de realizar una cobertura adecuada, semejante a la piel original, sin interferir con el desarrollo sexual normal del menor y minimizando el trauma psicológico. En el paciente adulto los resultados funcionales y estéticos son adecuados. En la literatura revisada hay muy pocos casos clínicos con utilización de ésta técnica.

To restore the cutaneous coverage in urgency injuries is a challenge for the surgeon, even more if it is a question of cutaneous coverage of the penis, by accidental degloving or secondary to septic processes of perineal región. We present two cases. The first one is a 9 years oíd minor, who lost the totality of his penis skin by accidental injury. The second case is a diabetic and hypertense, 65 years oíd patient, who had an episode of necrotizing fasciitis. In both cases the defect was covered with 2 fasciocutaneous flaps from the scrotal bags. In the child case the defect created in this area was repaired by an antero-internal thigh fasciocutaneous flap and finally the thigh defect was covered by split-skin grafts taken from the contralateral lower limb. The used technique fulfilled the objectives to make a suitable cover and similar to original skin, without interfering with the normal sexual development of the minor and to attenuate the psychological trauma. In the adult patient the functional and aesthetic results are satisfactory. In reviewed Hterature, there are just a few cases of this surgical technique.

Embarazo y parto vaginal en primigesta posterior a reconstrucción mamaria con colgajo TRAM / Pregnancy and vaginal delivery after transverse rectus abdominis musculocutaneous flap for breast reconstruction: report of one case

Introducción: La reconstrucción mamaria con colgajo miocutáneo transverso de recto anterior del abdomen (TRAM), es un recurso disponible en la rehabilitación del cáncer mamario. Existe poca literatura respecto de los cambios que experimenta la pared abdominal previamente debilitada con una gestación. Nuestro objetivo es divulgar nuestra experiencia en una paciente nuligesta, reconstruida con colgajo TRAM y que presentó embarazo de término por parto vaginal, sin incidentes. Material y Método: Análisis retrospectivo de ficha clínica. Paciente de 29 años sometida a radioterapia preoperatoria y mastectomía derecha simple extendida por cáncer mamario. Se realizó reconstrucción mamaria al año, con colgajo TRAM; se utilizó músculo recto unilateral, sin malla protésica, a los tres meses se reconstruyó pezón con injerto de piel perineal con técnica Skate-Flap. Se embarazó sin planificación en el postoperatorio inmediato de la reconstrucción de pezón. Inicia controles en unidad de alto riesgo obstétrico al quinto mes de gestación. Desarrolló un embarazo sin complicaciones, teniendo un parto vaginal de término con recién nacido masculino vivo de 2720 grs. El último control se realizó a los seis años, libre de enfermedad y no encontrándose hernia de la pared abdominal. Conclusiones: Los cambios que experimentó el abdomen, durante la gestación no afectaron la pared debilitada por la ausencia de uno de los músculos rectos abdominales. Se cumplió el objetivo de la reconstrucción mamaria respecto de recuperar la feminidad alterada por una mastectomía. El caso advierte al equipo médico respecto de tomar las precauciones ante la fertilidad en una mujer sexualmente activa.

Mammary reconstruction using Transverse Rectus Abdominis Musculocutaneos Flap (TRAM) is successfully used for mammary reconstruction after breast cancer surgery. The absence of the anterior rectus muscle modifies the functional properties of the abdominal wall. There is little knowledge about what occurs with a debilitated abdominal wall during pregnancy after mammary reconstruction using a TRAM flap. We report a 29 years old patient, who was treated for breast cancer with preoperative radiotherapy and a right side mastectomy with lymphadenectomy. TRAM flap was done one year later; a single rectus abdominis was used and the abdominal wall was not reinforced with a mesh. After three months, the nipple was reconstructed with the skate flap technique. Although it was not planned, she got pregnant and did not search for obstetric assessment until the fifth month. She was followed at the high risk obstetric unit and no complications were observed in her abdominal wall. She had a vaginal delivery of a healthy full term male newborn weighing 2720 grams. Six years later, there was no evidence of abdominal wall complications. Therefore, abdominal stress during pregnancy did not affect the debilitated abdominal wall after rotation of the rectus abdominis muscle.

The growth-defense trade-off and habitat specialization by plants in Amazonian forests.

Tropical forests include a diversity of habitats, which has led to specialization in plants. Near Iquitos, in the Peruvian Amazon, nutrient-rich clay forests surround nutrient-poor white-sand forests, each harboring a unique composition of habitat specialist trees. We tested the hypothesis that the combination of impoverished soils and herbivory creates strong natural selection for plant defenses in white-sand forest, while rapid growth is favored in clay forests. Recently, we reported evidence from a reciprocal-transplant experiment that manipulated the presence of herbivores and involved 20 species from six genera, including phylogenetically independent pairs of closely related white-sand and clay specialists. When protected from herbivores, clay specialists exhibited faster growth rates than white-sand specialists in both habitats. But, when unprotected, white-sand specialists outperformed clay specialists in white-sand habitat, and clay specialists outperformed white-sand specialists in clay habitat. Here we test further the hypothesis that the growth defense trade-off contributes to habitat specialization by comparing patterns of growth, herbivory, and defensive traits in these same six genera of white-sand and clay specialists. While the probability of herbivore attack did not differ between the two habitats, an artificial defoliation experiment showed that the impact of herbivory on plant mortality was significantly greater in white-sand forests. We quantified the amount of terpenes, phenolics, leaf toughness, and available foliar protein for the plants in the experiment. Different genera invested in different defensive strategies, and we found strong evidence for phylogenetic constraint in defense type. Overall, however, we found significantly higher total defense investment for white-sand specialists, relative to their clay specialist congeners. Furthermore, herbivore resistance consistently exhibited a significant trade-off against growth rate in each of the six phylogenetically independent species-pairs. These results confirm theoretical predictions that a trade-off exists between growth rate and defense investment, causing white-sand and clay specialists to evolve divergent strategies. We propose that the growth-defense trade-off is universal and provides an important mechanism by which herbivores govern plant distribution patterns across resource gradients.

The genome sequence of the gram-positive sugarcane pathogen Leifsonia xyli subsp. xyli.

The genome sequence of Leifsonia xyli subsp. xyli, which causes ratoon stunting disease and affects sugarcane worldwide, was determined. The single circular chromosome of Leifsonia xyli subsp. xyli CTCB07 was 2.6 Mb in length with a GC content of 68% and 2,044 predicted open reading frames. The analysis also revealed 307 predicted pseudogenes, which is more than any bacterial plant pathogen sequenced to date. Many of these pseudogenes, if functional, would likely be involved in the degradation of plant heteropolysaccharides, uptake of free sugars, and synthesis of amino acids. Although L. xyli subsp. xyli has only been identified colonizing the xylem vessels of sugarcane, the numbers of predicted regulatory genes and sugar transporters are similar to those in free-living organisms. Some of the predicted pathogenicity genes appear to have been acquired by lateral transfer and include genes for cellulase, pectinase, wilt-inducing protein, lysozyme, and desaturase. The presence of the latter may contribute to stunting, since it is likely involved in the synthesis of abscisic acid, a hormone that arrests growth. Our findings are consistent with the nutritionally fastidious behavior exhibited by L. xyli subsp. xyli and suggest an ongoing adaptation to the restricted ecological niche it inhabits.

Establishment of a functional genomics platform for Leifsonia xyli subsp. xyli.

Leifsonia xyli subsp. xyli, the causal agent of ratoon stunting disease in sugarcane, is a xylem-limited, nutritionally fastidious, slow growing, gram-positive coryneform bacterium. Because of the difficulties in growing this bacterium in pure culture, little is known about the molecular mechanisms of pathogenesis. Currently, the genome sequence of L. xyli subsp. xyli is being completed by the Agronomical and Environmental Genomes group from the Organization for Nucleotide Sequencing and Analysis in Brazil. To complement this work, we produced 712 Lxx::Tn4431 transposon mutants and sequenced flanking regions from 383 of these, using a rapid polymerase chain reaction-based approach. Tn4431 insertions appeared to be widespread throughout the L. xyli subsp. xyli genome; however, there were regions that had significantly higher concentrations of insertions. The Tn4431 mutant library was screened for individuals unable to colonize sugarcane, and one noncolonizing mutant was found. The mutant contained a transposon insertion disrupting two open reading frames (ORF), one of which had homology to an integral membrane protein from Mycobacterium leprae. Sequencing of the surrounding regions revealed two operons, pro and cyd, both of which are believed to play roles in disease. Complementation studies were carried out using the noncolonizing Lxx::Tn4431 mutant. The noncolonizing mutant was transformed with a cosmid containing 40 kbp of wild-type sequence, which included the two ORF disrupted in the mutant, and several transformants were subsequently able to colonize sugarcane. However, analysis of each of these transformants, before and after colonization, suggests that they have all undergone various recombinant events, obscuring the roles of these ORF in L. xyli subsp. xyli pathogenesis.

Uso de apósito semi-oclusivo adhesivo en quemaduras faciales / Use of semi-occlusive dressing in facial burns

Experiencia realizada a 27 pacientes ingresados por quemadura facial ABA y ABB mayores a 1 por ciento de la superficie corporal total, en quienes se usó un apósito adhesivo semioclusivo transparente de poliuretano. Un 46 por ciento fueron ABA y un 54 por ciento ABB. Se requirieron un promedio de 3 curaciones en las con quemaduras AB-A, con curación completa a los 9 días y 5 curaciones en las quemaduras AB-B, con curación completa a los 16 días. Con el uso de este apósitos, se obtienen los beneficios de la curación en ambiente húmedo permanente, alivia el dolor, favorece a la regeneración, acelera la curación, evita la profundización secundaria condicionada por la desecación evita la formación de costra, actúa como barrera para la contaminación externa, permite la observación constante de la quemadura, es menos limitante para el paciente y muy bien tolerado aun en pacientes menores de edad.

Precise matching of 3-D target models to multisensor data.

This paper presents a three-dimensional (3-D) model-based ATR algorithm that operates simultaneously on imagery from three heterogeneous, approximately boresight aligned sensors. An iterative search matches models to range and optical imagery by repeatedly predicting detectable features, measuring support for these features in the imagery, and adjusting the transformations relating the target to the sensors in order to improve the match. The result is a locally optimal and globally consistent set of 3-D transformations that precisely relate the best matching target features to combined range, IR, and color images. Results show the multisensor algorithm recovers 3-D target pose more accurately than does a traditional single-sensor algorithm. Errors in registration between images are also corrected during matching. The intended application is imaging from semiautonomous military scout vehicles.

Tratamiento del cáncer rectal / Treatment of rectal cancer

Se analiza la morbimortalidad, recidiva y sobrevida quinquenal de 99 pacientes tratados con intención curativa entre los años 1983 a 1992. Se trata de 51 mujeres y 48 hombres con una edad promedio de 59,4 años (17-90). Cincuenta y cuatro pacientes recibieron sólo cirugía y 46 además radioterapia coadyuvante. Veintidós Tu se localizaron en recto superior siendo tratados con RANT y HART, 28 en recto medio donde se agregaron tratamientos locales y AAP y 49 en recto inferior donde predominaron las AAP. El 50,5 por ciento de los pacientes presentaron alguna morbilidad siendo mayor en el grupo irradiado. La mortalidad global fue del 3 por ciento. Hubo diferencia significativa en la recidiva local la que se presentó más en el grupo no irradiado (40,3 por ciento vs 20,4 por ciento). La radioquimioterapia aumentó la resecabilidad de los Tu avanzados locales, disminuyendo en forma notable su recidiva local. La sobrevida global quinquenal fue del 44,8 por ciento siendo mejor en los pacientes con Tu localizados

The mechanism of low testosterone levels in homozygous sickle-cell disease.

Significantly lower testosterone levels are common in male patients with homozygous sickle-cell (SS) disease and have been attributed to either abnormalities of the hypothalamo-pituitary axis or primary testicular failure. The mechanism has now been investigated by observing the response to gonadotropin-thyrotropin releasing hormones (GnRH-TRH) in 10 male patients with SS disease and in 10 matched male sibling controls without sickle-cell disease. Mean basal levels of luteinizing hormone (LH), follicular stimulating hormone (FSH) and thyrotropin (TSH) were significantly elevated but prolactin (PRL) levels were within the normal range in the SS group. All hormones increased following GnRH-TRH, and proportionate increases over baseline were similar for FSH and TSH in SS and AA subjects, but SS patients showed a lesser percentage increase in LH at 30 minutes, and a higher percentage increase in PRL at 60 minutes. These observations are more consistent with primary testicular failure than with abnormalities of the hypothalamic-pituitary-testicular axis.

Urea kinetics in adults with homozygous sickle cell disease.

The kinetics of urea metabolism were measured in four adults with homozygous sickle cell disease (HbSS). On a dietary intake of 1.2 to 2.7 g protein/kg/d the rate of urea production was 188 to 277 mg nitrogen/kg/d. A relatively small proportion of the urea was excreted in the urine (40 per cent), with a high fixed rate of hydrolysis in the bowel, 145 mg nitrogen/kg/d. Although 50 per cent of the nitrogen from hydrolysed urea was resynthesized to urea, and a further 10 per cent may have been lost in the stool, it is estimated that 58 mg nitrogen/kg/d was available for synthetic metabolic activity. Urea kinetics in sickle cell disease subjects are markedly different from normals, and this may be a reflection of the metabolic demands for increased red cell synthesis.

Alpha thalassemia and the hematology of homozygous sickle cell disease in childhood.

alpha Thalassemia modifies the hematologic expression of homozygous sickle cell (SS) disease, resulting in increased total hemoglobin and HbA2 and decreased HbF, mean cell volume, reticulocytes, irreversibly sickled cells, and bilirubin levels. The age at which these changes develop in children with SS disease is unknown. Ascertainment of globin gene status in a large representative sample of children with SS disease has afforded an opportunity to study the hematologic indices in nine children homozygous for alpha thalassemia 2 (two-gene group), 90 children heterozygous for alpha thalassemia 2 (three-gene group), and 167 children with a normal alpha globin gene complement (four-gene group). The two-gene group had significantly lower mean cell volumes from birth, higher red cell counts from one month, lower reticulocytes from three months, and higher HbA2 levels from one year, as compared with the four-gene group. Children with three genes had intermediate indices but resembled more closely the four-gene group. Differences in total hemoglobin or in fetal hemoglobin between the groups were not apparent by eight years of age. The most characteristic differences of the two-gene group were the raised proportional HbA2 level and low mean cell volume, the latter having some predictive value for alpha thalassemia status at birth.