Herida crónica digital: ¿quiste epidermoide, osteomielitis o ambos? Presentación de dos casos clínicos y revisión de la literatura / Chronic digital wound: epidermoid cyst, osteomyelitis or both? Presentation of two clinical cases and review of the literature

Resumen: Introducción: ante una herida crónica a nivel digital se plantea el diagnóstico diferencial entre osteomielitis o tumor primario. No es infrecuente la coexistencia entre osteomielitis y quiste óseo epidermoide. Material y métodos: en este artículo describimos dos casos de quistes epidermoides en falange distal de la mano asociados a osteomielitis y se presenta una revisión de la literatura. Resultados: tanto la osteomielitis como el quiste óseo epidermoide se han relacionado con la presencia de un traumatismo previo en el sitio de la lesión, alteraciones ungueales y signos flogóticos crónicos, por lo que es importante llegar a un diagnóstico certero mediante un estudio anatomopatológico y realizar un buen desbridamiento quirúrgico que asegure la curación de ambas entidades. Conclusiones: el desbridamiento quirúrgico asociado a curetaje y relleno del defecto óseo con sustituto óseo por medio de antibiótico es una buena opción terapéutica en el tratamiento de estas lesiones.

Abstract: Introduction: when faced with a chronic digital injury, the differential diagnosis between osteomyelitis or primary tumor is raised. Coexistence between osteomyelitis and epidermoid bone cyst is not uncommon. Material and methods: in this article, we describe two cases of epidermoid cysts in distal phalanx of the hand associated with osteomyelitis and a review of the literature is presented. Results: both osteomyelitis and epidermoid bone cyst have been related to the presence of previous trauma at the site of the lesion, nail alterations and chronic phlogotic signs, so it is important to reach a diagnosis of certainty through an anatomopathological study and to perform a good surgical debridement to ensure the healing of both entities. Conclusions: surgical debridement associated with curettage and filling of the bone defect with bone substitute with antibiotic is a good therapeutic option in the treatment of these lesions.

Anaerobic RSH-dependent tellurite reduction contributes to Escherichia coli tolerance against tellurite

BACKGROUND: Tellurium is a rare metalloid that exerts high toxicity on cells, especially on bacteria, partly due to reactive oxygen species (ROS) generation. Moreover, it has also been observed that tellurite can target free cell thiols groups (RSH) (i.e. reduced glutathione (GSH)), enhancing the cellular redox imbalance. Additionally, in vitro experiments have suggested that several enzymes can reduce tellurite (IV) to its elemental form (0); where RSH present on their active sites may be responsible for the process. Nevertheless, the mechanisms implemented by bacteria for tellurite reduction and its role in resistance have not been evaluated in vivo. RESULTS: This work shows that tellurite reduction to elemental tellurium is increased under anaerobic conditions in E. coli cells. The in vivo tellurite reduction is related to the intracellular concentration of total RSH, in the presence and absence of oxygen. This metabolization of tellurite directly contributes to the resistance of the bacteria to the oxyanion. CONCLUSIONS: We demonstrated that in vivo tellurite reduction is related to the intracellular thiol concentration, i.e. large availability of cellular RSH groups, results in a more significant reduction of tellurite. Furthermore, we observed that, when the bacterium exhibits less resistance to the oxyanion, a decreased tellurite reduction was seen, affecting the growth fitness. Together, these results let us propose that tellurite reduction and the intracellular RSH content are related to the oxyanion bacterial resistance, this tripartite mechanism in an oxygen independent anaerobic process.

¿Cuáles son las barreras de acceso a la atención odontológica de las mujeres embarazadas? Una revisión de la literatura / What are the barriers of access to women's dental care pregnant? A review of the literature

Introducción: Las enfermedades bucales son altamente prevalentes a nivel mundial; una de las estrategias utilizadas para mejorar el estado de salud bucal de la población es la atención odontológica de la embarazada. En Chile esta atención está garantizada, sin embargo, la cobertura de las atenciones no es la esperada, sólo el 31 por ciento de las mujeres embarazadas accede a la atención odontológica y un 14 por ciento abandona el tratamiento antes de terminarlo. Métodos: El objetivo de este artículo es revisar la evidencia internacional y nacional respecto a las barreras que impiden a las mujeres embarazadas acceder al tratamiento odontológico. Resultados: Se describen diferentes barreras para la atención odontológica de la mujer embarazada, las que se pueden clasificar en las relacionadas con la organización del sistema de salud (costo de la atención, acceso a los prestadores y las características de los proveedores de la atención de salud) y las barreras personales (creencias de las pacientes, percepción de necesidad de tratamiento, miedo a la atención y valoración de la salud bucal). Conclusión: Existe evidencia internacional sobre cuáles son las barreras para el acceso a la atención odontológica de la mujer embarazada, entre ellas, destacan las barreras de acceso, como el costo de atención, sin embargo, a nivel nacional, esa barrera está soslayada, ya que el acceso y la protección financiera están garantizadas gracias a la cobertura GES. Por esta razón son necesarios estudios nacionales que indaguen sobre el fenómeno que impide que las embarazadas chilenas accedan al tratamiento odontológico.(AU)

Introduction: Oral diseases are highly worldwide prevalent; one of the strategies used to improve oral health status of the population is the specific pregnant women dental care program. In Chile this care is guaranteed by law, however, the dental attention coverage is not as well as expected, only 31% of pregnant women have access to dental care and 14percent of them, leave treatment before ending. Methods: The aim of this article is to review international and national evidence regarding the barriers that prevent pregnant women from accessing to dental treatment. Results: Different barriers are described. They can be classified in those related to the organization of the oral health system (care cost access to providers, care health providers characteristics) and personal barriers (patient's beliefs, perceived needs for treatment, fear and oral health assessment). Conclusion: There is international evidence about the barriers to access to pregnant women, dental care including barriers access such the care cost; however, at the national level, this barrier is overlooked since access and the financial protection is guaranteed by GES coverage. More studies are needed to investigate the phenomenon that avoids Chilean pregnant women from accessing to dental treatment.(AU)

Prevalencia de síntomas osteomusculares y factores asociados en los embaladores de leche en una pasteurizadora en Nemocón, Cundinamarca / Prevalence of musculoskeletal symptoms and factors associated in milk packers in a pasteurizer in Nemocón, Cundinamarca

Objetivo: Establecer la prevalencia de síntomas osteomusculares cervicobraquiales y su relación con el proceso de pasteurización de leche, en una comercializadora de lácteos en Nemocón, Cundinamarca. Metodología: Se realizó un estudio descriptivo de corte transversal en una pasteurizadora de leche, con una población de 18 trabajadores, a los cuales se les aplicó una encuesta basada en el Cuestionario Nórdico y el sugerido por NIOSH en busca de morbilidad sentida osteomuscular cervicobraquial, así como de información personal incluyendo edad, actividades extralaborales, tiempo de vida laboral, grado de satisfacción laboral, peso y talla, realizada para toda la población con los mismos instrumentos de medición. Se utilizaron frecuencias, porcentajes y unidades de tendencia central con base en promedios y porcentajes. Se emplearon test de Fisher y T de student. Resultado: La población estudiada fue en su totalidad de género masculino, con una mediana de 26 años de edad. El tiempo laborado en la empresa tuvo una mediana de 3,5 años. La prevalencia de síntomas por segmentos fue muy alta, siendo menor en cuello (16.7%) y mayor en mano y muñeca (88.9%). No se encontró diferencia entre la presencia de síntomas y la realización de actividades extralaborales ni con factores individuales como edad e índice de masa corporal. Tampoco se relacionó con la satisfacción laboral ni el tiempo de vida laboral. Discusión: Los resultados de este estudio muestran una alta prevalencia de síntomas osteomusculares en trabajadores de una pasteurizadora de leche, con exposición a factores de riesgo por carga física tanto postural, por movimiento repetitivo, como carga física, manipulación de cargas y exposición a frío, con la presencia de morbilidad sentida cervicobraquial osteomuscular. Dado que no se encontraron asociaciones significativas con los factores extralaborales e individuales evaluados, la alta prevalencia de sintomatología puede ser explicada por la exposición a carga física laboral.

T-DNA transfer from Agrobacterium tumefaciens to the ectomycorrhizal fungus Pisolithus microcarpus / Transferencia de T-DNA de Agrobacterium tumefaciens al hongo ectomicorrícico Pisolithus microcarpus

The model ectomycorrhizal fungus Pisolithus microcarpus isolate 441 was transformed by using Agrobacterium tumefaciens LBA1100 and AGL-1. The selection marker was the Shble gene of Streptoallotecius hidustanus, conferring resistance to phleomycin, under the control of the gpd gene promoter and terminator of Schizophyllum commune. Transformation resulted in phleomycin resistant clones which were confirmed by PCR to contain the resistance cassette. A. tumefaciens-mediated gene transfer would allow the development of RNA interference technology in P. microcarpus.

El hongo ectomicorrícico modelo Pisolithus microcarpus aislamiento 441 fue transformado utilizando Agrobacterium tumefaciens LBA 1100 y AGL-1. El marcador de selección fue el gen Shble de Streptoallotecius hidustanus, el cual confiere resistencia a fleomicina, bajo el control del promotor y terminador del gen gpd de Schizophyllum commune. La transformación resultó en clones resistentes a fleomicina comprobándose por PCR la presencia del transgen. La transferencia génica mediada por Agrobacterium podría permitir el desarrollo de la tecnología de interferencia por ARN en P. microcarpus.

Prevalencia al nacimiento de aberraciones cromosómicas en el Hospital Clínico de la Universidad de Chile. Período 1990-2001 / Prevalence of chromosomal aberrations at birth in the Clinical Hospital of Universidad de Chile, 1990-2001

BACKGROUND: A cytogenetical study should be performed to every newborn with malformations. If a chromosomal aberration is found, parents must be studied to give an adequate genetic advise. AIM: To study the frequency of chromosomal aberrations in newborns with malformations. PATIENTS AND METHODS: In the Clinical Hospital of the University of Chile all malformations in newborns are registered, as part of the Collaborative Latin American Study of Congenital Malformations (ECLAMC). The frequency of chromosomal aberrations, determined by cytogenetical studies, was determined in newborns with malformations. RESULTS: In the study period, there were 32,214 births. Of these, 2,268 live newborns and 43 stillbirths had malformations. Ninety nine children with malformations had chromosomal aberrations (4.3 per cent). Trisomy 21 was the most common aberration with a rate of 23/10,000 births, followed by trisomy 18 with a rate of 4/10,000 and trisomy 18 with a rate of 1.2/10,000. Ninety four percent of these children were born alive and 16.1 per cent died before discharge from the hospital. The masculinity indexes for Down syndrome and for trisomy 18 were 0.38 and 0.61 respectively. CONCLUSIONS: A higher frequency of female gender for trisomy 21 and male gender for trisomy 18 has not been reported previously.

Cellulose and xylan degrading enzymes in Thecotheus pelletieri

The ability to produce cellulose and xylan degrading enzymes by different strains of Thecotheus pelletieri, in liquid synthetic media with cellulose and xylan as inducers, was compared. All the strains tested were able to grow and produce cellulases and xylanases, being the strain BAFC 2077 the best producer. Several cultural conditions were analysed in order to optimise enzyme production by strain 2077. Shaking cultures gave higher yields of cellulases and xylanases compared with stationary ones. Asparagine at 0.75 g N/L was the best nitrogen source in promoting enzyme production. The influence of different surfactants on enzyme production was studied. Tween 80 exhibited no effect on growth and enzyme production, whereas Tween 20 and Triton X-100 were inhibitory. By means of studies of variation of cellulose/xylan ratio in the culture medium we determined that cellulose and xylan induced cellulase and xylanase synthesis, being the specific substrates the most effective. The inducible behavior of cellulases and xylanases in T. pelletieri was determined by means of inhibition of protein synthesis by cycloheximide and ethidium bromide. Moreover, we found that glucose as well as xylose repressed cellulase and xylanase synthesis in T. pelletieri.

Influence of temperature and pH on cellulase activity and stability in Nectria catalinensis

The influence of temperature and pH on the activity and stability of the cellulase system (endoglucanase, exoglucanase and cellobiase) was investigated in Nectria catalinensis. Optimal temperature for the activity of the cellulase system ranged from 50 to 55 degrees C, with an optimum for stability between 23 degrees C and 37 degrees C after a 72 h incubation period. For the different enzymes, maximal activity was registered between pH 4.2-5.8, with pH 4.8 being close to optimal for all stability studies. The activation energy was 4.97 Kcal mol-1 for endoglucanase, 4.37 Kcal mol-1 for exoglucanase and 13.73 Kcal mol-1 for cellobiase. The K(m) and Vmax values were 1.73 mg CMC ml-1 and 0.45 mumol glucose min-1 mg protein-1 for endoglucanase, 0.22 mg microcrystalline cellulose ml-1 and 57.1 nmol glucose min-1 mg protein-1 for exoglucanase, and 2.95 mM cellobiose and 0.17 mumol glucose min-1 mg protein-1 for cellobiase.

Matrix metalloproteinases and lung injury

The dynamic equilibrium of extracellular matrix (ECM) under different physiological conditions is a consequence of the balance between the regulation of synthesis and degradation of ECM components. Matrix metalloproteinases (MMPs), a family of structurally related zinc-dependent endopeptidases, are the physiological mediators of matrix remodeling. The expression and activity of these enzymes are highly regulated at several intra- and extracellular levels, so that in vivo enzymatic activity is the final result of a complex series of events including gene expression, zymogen activation, matrix binding, and enzymatic inhibition. MMPs are expressed at low levels in normal adult tissues, and their upregulation appears to play an important role in the development of a number of pathological processes. In acute lung injury, a disorder characterized by a severe disruption of the gas exchange alveolo-capillary structures, the upregulation of interstitial collagenase and gelatinases A and B strongly suggests that MMPs contribute to acute lung damage by facilitating the migration of inflammatory cells, as well as to the disruption of basement membrane components and extracellular matrix remodeling.

Pathogenic mechanisms in the development of diffuse pulmonary fibrosis

Diffuse pulmonary fibrosis is characterized by abnormal proliferation of mesenchymal cells, specifically fibroblasts and myofibroblasts, and by the accumulation of excessive amounts of matrix proteins, mainly collagens. The development of this pathological process is preceded by an inflammatory response, often dominated by macrophages and lymphocytes, which is mediated by the local release of chemoattractant factors, acting coordinately with an upregulation of cell-surface adhesion molecules. A subsequent persisting fibroproliferative reaction, in both interstitial and intraalveolar spaces, with progressive collagen accumulation distorts the lung architecture irreversibly. Excessive collagen deposition is the result of an imbalance in the collagen turnover rates characterized by a transient increase in collagen synthesis and a decrease in collagen degradation. Fibrosis is considered otherwise to be the final common pathway of a variety of lung disorders, and in this context, the diagnosis of pulmonary fibrosis implies the recognition of an advanced stage in the evolution of a complex process of abnormal repair.

Esclerosis en hemorragia de vías digestivas altas de origen no varicoso

Se presentan 67 casos de hemorragia digestiva alta de origen no varicoso, a saber angiodisplasia gástrica, síndrome Mallory-Weiss, úlcera gástrica y duodenal. Se trataron 17 pacientes mediante esclerosis endoscópica con una solución de adrenalina al 1:10000 en solulucón salina normal, de los cuales 15 respondieron con la primera sesión, 2 debieron ser reesclerosados y uno sometido a cirugía. De los 50 no esclerosados, 4 fueron llevados a cirugía y uno falleció antes. Los 45 restantes respondieron a tratamiento médico convencional. se analizan las ventajas del procedimiento y se revisan las otras técnicas de hemostasia endoscópica