Magnetic-Responsive Carbon Nanotubes Composite Scaffolds for Chondrogenic Tissue Engineering.

The demand for engineered scaffolds capable of delivering multiple cues to cells continues to grow as the interplay between cell fate with microenvironmental and external cues is revealed. Emphasis has been given to develop stimuli-responsive scaffolds. These scaffolds are designed to sense an external stimulus triggering a specific response (e.g., change in the microenvironment, release therapeutics, etc.) and then initiate/modulate a desired biofunction. Here, magnetic-responsive carboxylated multi-walled carbon nanotubes (cMWCNTs) are integrated into 3D collagen/polylactic acid (PLA) scaffold via a reproducible filtration-based method. The integrity and biomechanical performance of the collagen/PLA scaffolds are preserved after cMWCNT integration. In vitro safety assessment of cMWCNT/collagen/PLA scaffolds shows neither cytotoxicity effects nor macrophage pro-inflammatory response, supporting further in vitro studies. The cMWCNT/collagen/PLA scaffolds enhance chondrocytes metabolic activity while maintaining high cell viability and extracellular matrix (i.e., type II collagen and aggrecan) production. Comprehensive in vitro study applying static and pulsed magnetic field on seeded scaffolds shows no specific cell response in dependence with the applied field. This result is independent of the presence or absence of cMWCNT into the collagen/PLA scaffolds. Taken together, these findings provide additional evidence of the benefits to exploit the CNTs outstanding properties in the design of stimuli-responsive scaffolds.

Langerhans Cell Histiocytosis-A Benign Presentation Heralding a Serious Disease.

A 3-year old White boy was referred to our dermatology department with a papular disseminated eruption, evolving for 7 months. Several topical antibiotics and corticosteroids were used without improvement. The dermatosis was locally asymptomatic, and systemic symptoms were absent. Examination revealed multiple, skin-colored to pinkish monomorphic papules with a generalized distribution involving the face, trunk, and limbs (Figure 1). The lesions spared the scalp, palms, and soles. Cervical, axillary, and inguinal lymphatic nodes were not palpable. Cutaneous biopsy of one of the abdominal lesions revealed an unremarkable epidermis but a reticular dermis with clusters of histiocytic, lymphocytic, and rare eosinophil cells. In the immunohistochemical study, expression of CD1a was observed in the histiocytic cells and S100 in the antigen-presenting cells of the dermal infiltrate (Figures 2 and 3). Taking into account the clinical presentation and the histopathologic result, a diagnosis of Langerhans cell histiocytosis (LCH) was established.

The Chemistry of Diet: Medicine, Nutrition, and Staple Foods in Imperial Brazil.

Brazilian cuisine is much admired by present-day international chefs. However, in the nineteenth century, local ingredients and recipes were looked down upon by the Portuguese colonists, as well as by visiting European naturalists. This fact, together with medical and chemical views formulated throughout the 1800s, led locally trained doctors to attribute the occurrence of countless diseases that devastated Rio de Janeiro to local staple foods, particularly corn and manioc flour. In the first part of the present article, I review the dietary habits of Brazilians through the eyes of European naturalists who travelled across the country in the early nineteenth century. In the second part, I summarise the ideas formulated by French and German chemists on the components, and consequent nutritional value, of cereals and other sources of flour, and then analyse the appropriation of such ideas--particularly those of Justus Liebig--by Brazilian doctors and their adaptation to local conditions.

Acute Acalculous Cholecystitis by Epstein-Barr Virus Infection: A Rare Association.

Acute acalculous cholecystitis (AAC) is a rare complication of Epstein Barr virus (EBV) infection, with only a few cases reported among pediatric population. This clinical condition is frequently associated with a favorable outcome and, usually, a surgical intervention is not required. We report a 16-year-old girl who presented with AAC following primary EBV infection. The diagnosis of AAC was documented by clinical and ultrasonographic examination, whereas EBV infection was confirmed serologically. A conservative treatment was performed, with a careful monitoring and serial ultrasonographic examinations, which led to the clinical improvement of the patient. Pediatricians should be aware of the possible association between EBV and AAC, in order to offer the patients an appropriate management strategy.