Direct enzymatic hydrolysis of solid wheat straw with endo-xylanases: Effect of the temperature on the hemicellulose release and the product profile modulation.

Prebiotics are non-digestible compounds that promote intestinal microbiota growth and/or activity. Xylooligosaccharides (XOS) are new prebiotics derived from the hemicellulose fraction of lignocellulosic materials. Challenges in using those materials as sources for prebiotic compounds lie in the hemicellulose extraction efficiency and the safety of those ingredients. In this sense, this work aims to optimize hemicellulose extraction and XOS production through direct enzymatic hydrolysis of alkali pre-treated wheat straw without undesired byproducts. By increasing the temperature of the enzymatic step from 40 °C to 65 °C we achieved an improvement in the extraction yield from 55 % to 80 %. Products with different degrees of polymerization were also noticed: while XOS ≤ X6 where the main products at 40 °C, a mixture of long arabinoxylan derived polymers (ADPo) and XOS ≤ X6 was obtained at 65 °C, irrespective of the extraction yield. Thus, a modulatory effect of temperature on the product profile is suggested here. Among the XOS ≤ X6 produced, X2-X3 were the main products, and X4 was the minor one. At the end of the hydrolysis, 146.7 mg XOS per gram of pre-treated wheat straw were obtained.

Lipedematous scalp. A rare entity in the pediatric ageLipedema de cuero cabelludo: una entidad infrecuente en pediatría.

Lipedematous scalp is an uncommon entity of unknown etiology, rarely described in the pediatric age. It is characterized by boggy thickening of the scalp predominantly located at the vertex and occiput, which acquires a cotton-like consistency. This condition is palpable rather than visible. It is a casual finding because it is usually asymptomatic, although it may involve alopecia, pruritus, or dysesthesia. We report a 10-year-old girl with lipedematous scalp without alopecia. Sonographic and MRI findings confirmed the diagnosis of lipidematous scalp.  El lipedema de cuero cabelludo o cuero cabelludo lipedematoso es una entidad infrecuente y de etiología desconocida, rara vez descrita en la edad pediátrica. Se caracteriza por un engrosamiento difuso y de tacto esponjoso del tejido celular subcutáneo localizado principalmente en vértex y occipucio. Suele ser un hallazgo casual dado que habitualmente cursa de forma asintomática, aunque puede asociar alopecia, prurito o disestesias. Presentamos el caso de una niña de 10 años de edad con lipedema de cuero cabelludo sin alopecia asociada. Los hallazgos ecográficos y de resonancia magnética confirmaron el diagnóstico de lipedema de cuero cabelludo.

Dermatitis perianal estreptocócica: estudio clínico-epidemiológico de 95 episodios / Perianal streptococcal dermatitis: clinical and epidemiological study of 95 episodes

INTRODUCCIÓN Y OBJETIVOS: analizar las características clínico-epidemiológicas de la dermatitis perianal por estreptococo betahemolítico del grupo A (SBHGA). MATERIAL Y MÉTODOS: serie de casos con recogida prospectiva de datos durante un periodo de ocho años en una consulta de Pediatría. RESULTADOS: se diagnosticaron 95 episodios (1/298 consultas) en 76 niños (varones/mujeres: 1,6/1). Edad media 4,5 años. Padecieron más de un episodio 13 pacientes con un total de 19 episodios sucesivos: 10 de ellos en un periodo inferior a 6 meses respecto al anterior (11% del total de episodios). Los motivos de consulta más frecuentes fueron: prurito, sangrado, dolor, estreñimiento y eritema perianal. El tratamiento se realizó por vía tópica en el 70% de los primeros episodios y combinado (tópico y sistémico) en el 68% de los sucesivos. Se constató un fracaso terapéutico inicial en tres episodios. La distribución estacional fue similar a la de faringoamigdalitis y escarlatinas por SBHGA diagnosticadas en el mismo periodo. CONCLUSIONES: cinco motivos de consulta (prurito, sangrado, dolor, estreñimiento y eritema perianal), solos o combinados, estuvieron presentes en el 92% de los episodios. En solo el 17% de los primeros episodios el eritema perianal fue motivo de consulta. Puede ser tenue, sus bordes no siempre son nítidos y en ocasiones asocia lesiones satélites

INTRODUCTION AND OBJECTIVES: to analyse the clinical and epidemiological characteristics of perianal dermatitis cases caused by group A beta-haemolytic streptococcus (GABHS). MATERIAL AND METHODS: prospective case series with collection of data for a period of 8 years in an outpatient paediatrics clinic. RESULTS: there were 95 episodes (1/298 visits) diagnosed in 76 children (predominantly boys, 1.6/1). The mean age was 4.5 years. Thirteen patients had more than one episode, with a total of 19 recurrent episodes, 10 of them within 6 months of the previous episode (11% of the total number of episodes). The most frequent presenting complaints were itching, bleeding, pain, constipation and perianal erythema. Treatment was topical in 70% of the initial episodes, and combination therapy (topical and systemic) was used in 68% of recurrent episodes. The initial treatment failed in 3 cases. The seasonal case distribution was similar to that of pharyngotonsillitis and scarlet fever caused by GABHS in the same time period. CONCLUSIONS: five presenting complaints (itching, bleeding, pain, constipation and perianal erythema), alone or in combination, were present in 92% of the episodes. Perianal erythema was the presenting complaint in only 17% of the first episodes. Erythema can be faint and its borders are not always well demarcated, and may manifest with associated satellite lesions

Delayed aminopenicillin reaction associated to human herpes virus 6 infection mimicking DRESS syndrome.

BACKGROUND: DRESS syndrome (rash with eosinophilia and systemic symptoms) is an uncommon and severe drug-induced reaction. CLINICAL CASE: An 8-year-old boy was diagnosed with tonsillopharyngitis, and treatment with amoxicillin was started. One day later, he presented bilateral malar rash which evolved to generalized erythroderma in two days. He was referred to the emergency room and then he was discharged after the treatment with amoxicillin was discontinued. Five days later, he still had fever, progressive facial and acral edema, and ecchymotic lesions. The laboratory studies showed 6220 leukocytes/mm3 (970 eosinophils/mm3). The pharyngeal culture tested positive to human herpesvirus 6 (HHV-6). The fever, rash and edema disappeared with supportive measures. Based on the results of the allergy tests, a diagnosis of delayed reaction to aminopenicillin associated to HHV-6 mimicking DRESS syndrome was made, with the recommendation to avoid penicillin antibiotics. CONCLUSION: The diagnosis of delayed reactions to aminopenicillin and DRESS syndrome requires a high index of suspicion in order to promptly withdraw the offending medication and to avoid delays in the diagnosis.

Antecedentes: El síndrome DRESS (erupción que cursa con eosinofilia y síntomas sistémicos) es una reacción inducida por fármacos poco frecuente y grave. Caso clínico: Niño de ocho años a quien se prescribió tratamiento con amoxicilina debido a diagnóstico de amigdalofaringitis. Un día después del inicio del medicamento, el paciente presentó erupción malar bilateral que evolucionó a eritrodermia generalizada en dos días. Fue derivado al servicio de urgencias donde se interrumpió el tratamiento con amoxicilina y fue dado de alta. Cinco días después, todavía tenía fiebre, edema facial y acral progresivo y lesiones equimóticas. Los estudios de laboratorio mostraron 6220 leucocitos/mm3 (970 eosinófilos/mm3). El cultivo faríngeo fue positivo al virus de herpes humano 6. La fiebre, la erupción y el edema desaparecieron con medidas de apoyo. Con base en los resultados de las pruebas de alergia, se realizó un diagnóstico de reacción tardía a la aminopenicilina asociada con herpesvirus de humano 6 que simulaba síndrome DRESS. La recomendación fue evitar los antibióticos con penicilina. Conclusiones: El diagnóstico de reacciones tardías a la aminopenicilina y el síndrome DRESS requieren un alto índice de sospecha para retirar rápidamente la medicación desencadenante y evitar retrasos en el diagnóstico.

Effectiveness of proteolytic enzymes to remove gluten residues and feasibility of incorporating them into cleaning products for industrial purposes.

The development of protocols for efficient gluten elimination is one of the most critical aspects of any allergen management strategy in the industry. The suitability of different proteolytic enzymes to be included in a cleaning formulation that allows the effective elimination of gluten residues was studied. Alcalase (ALC), neutrase (NEUT) and flavourzyme (FLAV) were selected from in silico analysis. The presence of 1% (v/v) of linear alkylbenzene sulphonate (LAS), a common anionic detergent, improved the gluten solubility, which may favour its elimination. Chromatographic analysis showed that the three enzymes studied were able to hydrolyse gluten in the presence of LAS. The highest percentage of short peptides (< 5 kDa) was achieved with ALC, what increases the probability of reducing the gluten antigenicity. Besides, in the presence of ALC and detergent LAS have detected the lowest levels of gluten with ELISA kits. So, effective amounts of ALC and LAS were added to a cleaning formulation, where its proteolytic activity was maintained above 90% after 37 days at 4 °C and 25 °C (under dark). Preliminary validation of the effectiveness enzymatic cleaning formulation to hydrolyse gluten was performed in a ready-to-eat/frozen food company, in which previous episodes of cross-contamination with gluten have been detected. The gluten content decreased to values below 0.125 µg/100 cm2 when the cleaning formulation was tested on different surfaces with different cleaning protocols, demonstrating the high suitability of the enzymatic cleaning formulation developed.

Aplasia cutis congénita con defecto óseo subyacente: evolución favorable tras manejo conservador.

La aplasia cutis congénita es una rara alteración caracterizada por la ausencia de áreas localizadas de piel en el momento del nacimiento. Suele manifestarse como una lesión solitaria localizada principalmente en el cuero cabelludo, que puede estar asociada con otras malformaciones congénitas. Las complicaciones pueden ser fatales, por lo que es necesario un tratamiento individualizado que vendrá determinado por el tamaño, localización y grado de afectación de estructuras subyacentes. Presentamos un caso de aplasia cutis congénita del cuero cabelludo con múltiples lesiones y defecto óseo subyacente de 3 × 1.5 cm de tamaño, pero sin otras anomalías asociadas. El manejo conservador permitió una adecuada y completa epitelización cutánea con cierre del defecto óseo subyacente sin necesidad de procedimientos invasivos.

Temperature- and pH-sensitive nanohydrogels of poly(N-Isopropylacrylamide) for food packaging applications: modelling the swelling-collapse behaviour.

Temperature-sensitive poly(N-isopropylacrylamide) (PNIPA) nanohydrogels were synthesized by nanoemulsion polymerization in water-in-oil systems. Several cross-linking degrees and the incorporation of acrylic acid as comonomer at different concentrations were tested to produce nanohydrogels with a wide range of properties. The physicochemical properties of PNIPA nanohydrogels, and their relationship with the swelling-collapse behaviour, were studied to evaluate the suitability of PNIPA nanoparticles as smart delivery systems (for active packaging). The swelling-collapse transition was analyzed by the change in the optical properties of PNIPA nanohydrogels using ultraviolet-visible spectroscopy. The thermodynamic parameters associated with the nanohydrogels collapse were calculated using a mathematical approach based on the van't Hoff analysis, assuming a two-state equilibrium (swollen to collapsed). A mathematical model is proposed to predict both the thermally induced collapse, and the collapse induced by the simultaneous action of two factors (temperature and pH, or temperature and organic solvent concentration). Finally, van't Hoff analysis was compared with differential scanning calorimetry. The results obtained allow us to solve the problem of determining the molecular weight of the structural repeating unit in cross-linked NIPA polymers, which, as we show, can be estimated from the ratio of the molar heat capacity (obtained from the van't Hoff analysis) to the specific heat capacity (obtained from calorimetric measurements).