Cell Retention as a Viable Strategy for PHA Production from Diluted VFAs with Bacillus megaterium.

The production of biodegradable and biocompatible materials such as polyhydroxyalkanoates (PHAs) from waste-derived volatile fatty acids (VFAs) is a promising approach towards implementing a circular bioeconomy. However, VFA solutions obtained via acidification of organic wastes are usually too diluted for direct use in standard batch or fed-batch processes. To overcome these constraints, this study introduces a cell recycle fed-batch system using Bacillus megaterium uyuni S29 for poly(3-hydroxybutyrate) (P3HB) production from acetic acid. The concentrations of dry cell weight (DCW), P3HB, acetate, as well as nitrogen as the limiting substrate component, were monitored during the process. The produced polymer was characterized in terms of molecular weight and thermal properties after extraction with hypochlorite. The results show that an indirect pH-stat feeding regime successfully kept the strain fed without prompting inhibition, resulting in a dry cell weight concentration of up to 19.05 g/L containing 70.21% PHA. After appropriate adaptations the presented process could contribute to an efficient and sustainable production of biopolymers.

Langerhans cell hyperplasia of the skin mimicking Langerhans cell histiocytosis: a report of two cases in children not associated with scabies.

Langerhans cells histiocytosis (LCH) affecting the skin most commonly has clinical and histopathologic diagnostic features. We are reporting two examples of Langerhans cell (LC) hyperplasia recognized in the skin biopsies of two children initially interpreted as LCH. The first was an 8-year-old boy finally interpreted as having an atypical type of contact dermatitis, while the second, an 8-year-old girl, was assumed to have Pytiriasis lichenoides et varioliformis acuta. None showed evidences of scabies. Both presented spongiotic dermatitis with numerous CD1a+ cells. As more cases of LC hyperplasia are recognized, new details emerge helping in the differential diagnosis. Strict clinical-pathologic correlation is suggested in order to avoid misdiagnosis.

Dermatosis congénita vesicular y erosiva con cicatrices reticuladas. Presentación de un caso y revisión de la literatura / Congenital erosive and vesicular dermatosis healing with reticulated supple scarring. A case report and review of the literature

La dermatosis congénita vesicular y erosiva con cicatrices reticuladas es un raro desorden cutáneo de etiología desconocida con lesiones evidentes al nacimiento. Presentamos una niña con esta condición, la cual representa el primer caso diagnosticado en la Argentina, junto a una revisión dela literatura.

Congenital erosive and vesicular dermatosis healing with reticulated, supple scarring is a rare cutaneouscondition of unknown etiology. It presents with patchy or generalized erosion and vesiclesrecognizable at birth, that heal with reticulated scarring. We report a female child with thiscondition, the first recognized in Argentina, together with a review of the literature.

Dermatosis pustular erosiva en el cuero cabelludo de una niña / Erosive pustular dermatosis of the scalp of a girl

La dermatosis pustular erosiva del cuero cabelludo es una erupción pustular idiopática que se ha asociado al trauma físico, quirúrgico o a tratamientos médicos. Se presenta una niña que desarrolla este cuadro como consecuencia del trauma quirúrgico provocado por el drenaje de múltiples abscesos en el cuero cabelludo

Erosive pustular dermatosis of the scalp is characterized by idiopathic pustular eruption often triggered by physical, medical or surgical trauma. We present a girl of 6 years of age that developed this disease as a consequence of surgical trauma after multiple scalp abscesses drainage

Urticaria vasculitis en una niña de cinco años / Urticarial vasculitis in a girl of five years

La urticaria-vasculitis es una forma de vasculitis que se presenta en forma de habones eritematosos clínicamente semejantes a la urticaria hemorrágica de tipo alérgica, pero que histológicamente muestra cambios de vasculitis leucocitoclástica. Puede acompañarse de normocomplementemia o hipocomplementemia. En ambas situaciones puede estar asociada a síntomas sistémicos (como por ejemplo, angioedema, artralgias, dolor abdominal, fiebre, enfermedad pulmonar o renal, epiescleritis y uveitis), aunque en los casos en que se acompaña de hipocomplementemia ha sido vinculada con mayor frecuencia a enfermedades del tejido conectivo. El estudio histopatológico permite diferenciar la urticaria hemorrágica alérgica de la urticaria-vasculitis. Presentamos una niña de 5 años con urticaria-vasculitis y normocomplementemia, con lesiones cutáneas típicas asociadas a artralgias y dolor abdominal.

Urticarial vasculitis is an eruption of erythematous wheals that clinically resemble urticaria but histollogicaly shows leukocytoclastic vasculitis. Urticarial vasculitis may be divided into normocomplementemic and hypocomplementemic variants. Both subsets can be associated with systemic symptoms (for example, angioedema, arthralgias, abdominal or chest pain, fever, pulmonary or renal disease, epiescleritis and uveitis), more often the second variant which has been linked to connective-tissue disease. Histopathological evaluation allows to differentiate between hemorrhagic allergic urticaria and urticarial vasculitis. We report the case of a 5-year-old girl presenting with normocomplementemic uticarial vasculitis, with typical cutaneous lesions associated to arthralgias and abdominal pain.