Inmovilización de lacasas en esferas de SiO₂ para la degradación de rojo congo

Propósito y Método de Estudio: Las lacasas son enzimas extracelulares que tienen la capacidad de oxidar una amplia variedad de sustratos utilizando al oxígeno como aceptor de electrones. Debido a esto, se ha utilizado esta enzima para diversas aplicaciones biotecnológicas dentro de las cuales destaca la degradación de colorantes textiles. En este trabajo se inmovilizaron tres tipos de lacasas, dos a partir de hongos de pudrición blanca (lacasa-HPB y lacasa HTT) y una comercial del género Trametes versicolor (lacasa-EC), en esferas mesoporosas de dióxido de silicio modificado para la degradación del colorante tipo azo rojo congo y azul índigo. Las lacasas HPB y HTT fueron purificadas a partir de la fermentación líquida optimizada de los hongos de pudrición blanca. Posteriormente se inmovilizaron mediante enlace covalente con el soporte (SiO2) y se realizaron las cinéticas de actividad enzimática y de degradación de los colorantes rojo congo y azul índigo. Contribuciones y Conclusiones: Se encontraron las condiciones de máxima producción de lacasa para los hongos seleccionado (HPB) y el hongo de referencia (HTT), observando que la producción de las lacasas se ve favorecida cuando el medio de cultivo contiene materiales ligninocelulósicos. Además se purificaron lacasas a partir de los extractos de los hongos HPB y HTT obteniendo pesos molecuares de aproximadamente 67 kDa lo que concuerda con lo reportado para las lacasas monoméricas. Se inmovilizaron las lacasas-EC, lacasas-HPB y lacasas-HTT en esferas mesoporosas de dióxido de silicio reteniendo un 56.94%, 55.68% y 46.08% de su actividad inicial respectivamente. En la degradación del colorante rojo congo con las enzimas inmovilizadas se obtuvieron porcentajes de decoloración de un 92.2%, 61.9% y 42.2% para la lacasa-EC, lacasa-HPB y lacasa-HTT en un tiempo de 60 minutos. Para el colorante azul índigo los porcentajes de degradación fueron de 89.2%, 62.1% y 50.3% para la lacasa-EC, lacasa-HPB y lacasa-HTT en 90 minutos. Por los resultados anteriores se muestra que la inmovilización enzimática de lacasas en SiO2 mesoporoso modificado con aminas, es una opción recomendable en el tratamiento de efluentes textiles, ya que los porcentajes de degradación se favorecen por el aporte que presenta el soporte en la degradación debido a la adsorción del colorante, disminuyendo por lo tanto los tiempos de proceso de tratamiento de efluentes acuosos con colorantes.

Laryngeal amyloidosis: An uncommon cause of dysphonia

Introduction: Amyloidosis is used to describe a range of disorders deined by extracellular deposition of abnormal protein ibrils. The larynx is the most common site of localized amyloidosis in the head and neck region and constitutes less than 1% of benign laryngeal lesions. Hoarseness is the most common symptom. Objective: Prospective clinical evaluation of patients with localized laryngeal amyloidosis. Clinical cases: Presented are 4 cases of patients with localized laryngeal amyloidosis who were treated at the Otolaryngology and Head and Neck Surgery Department at the “Dr. José Eleuterio González” University Hospital in Monterrey, Mexico. Three patients underwent phonomicrosurgery by direct microlaryngoscopy with the removal of the amyloid implantation using a cold knife excision with great results. In each patient the major site of involvement was the supraglottis with a small focus on the false vocal cord. A medical work-up, including a complete blood count (CBC), a basic metabolic panel, urinalysis, liver function test, chest X-ray and physical examination were performed to rule out the presence of systemic disease; no amyloidosis or signs of systemic disease were found. Congo red staining conirms the diagnosis of amyloidosis in all surgical specimens. Conclusions: In laryngeal amyloidosis, the treatment should be directed toward the improvement of the voice and the maintenance of the airway.

Ebola virus disease 2014

Ebola virus disease was irst described in 1976 originating from the Ebola River in the Democratic Republic of Congo. Since then, Ebola virus has become an important public health threat in Africa, and now it is of great concern worldwide due to the recent outbreaks (9216 cases with 4555 deaths up to October 20th, 2014), and it is so far the largest and deadliest recorded in history. Five Ebola virus species have been identiied (including Zaire, Sudan, Ivory Coast, Reston, and Bundibugyo Ebola virus), and four of them have proved to be highly pathogenic for both human and non-human primates, causing viral hemorrhagic fever with case fatality rates of up to 90%, for which no approved therapeutics or vaccines are currently available. Ebola virus infections are characterized by immune suppression and a systemic inlammatory response that causes impairment of the vascular, coagulation, and immune systems, leading to multiorgan failure and shock, and thus, in some ways, resembling septic shock. The major affected countries, Sierra Leone, Guinea, Liberia, and Nigeria, have been struggling to contain and to mitigate the outbreak. Gene sequencing of the 2014 virus (2014WA) outbreak has demonstrated 98% homology with the Zaire Ebola virus, with a 49% case fatality ratio across the affected countries. In this review the characteristics of the viruses, pathogenesis, diagnosis, treatment, and the cases reported in health care workers (HCW) are described, as well as a summary of outbreaks of the virus since its discovery, including these last two outbreaks in Africa.