In situ cross-linked hydrogels have the advantage of effectively fulfilling the wound in its shape and depth. Amongst the new generation of natural-based biopolymers being proposed for wound care and skin regeneration, silk sericin is particularly interesting due to its exceptional properties such as biocompatibility, biodegradability, and antioxidant behavior, among others. In this study, a new enzyme-mediated cross-linked hydrogel composed of silk sericin is proposed for the first time. The developed hydrogel cross-linking strategy was performed via horseradish peroxidase, under physiological conditions, and presented gelling kinetics under 3 min, as demonstrated by its rheological behavior. The hydrogels presented a high degree of transparency, mainly due to their amorphous conformation. Degradation studies revealed that the hydrogels were stable in phosphate buffer solution (PBS) (pH 7.4) for 17 days, while in the presence of protease XIV (3.5 U/mg) and under acute and chronic physiological pH values, the stability decreased to 7 and 4 days, respectively. During protease degradation, the present sericin hydrogels demonstrated antioxidant activity. In vitro studies using an L929 fibroblast cell line demonstrated that these hydrogels were noncytotoxic, promoting cell adhesion and massive cell colonization after 7 days of culture, demonstrating that cells maintained their viability and proliferation. In addition, the application of sericin-based hydrogel in an in vivo diabetic wound model validated the feasibility of the in situ methodology and demonstrated a local anti-inflammatory effect, promoting the healing process. This study presents a simple, fast, and practical in situ approach to produce a sericin-based hydrogel able to be applied in low exudative chronic wounds. Moreover, the study herein reported fosters the valorization of a textile industrial by-product by its integration in the biomedical field.

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The murine model has been widely used to study the host immune response to Neospora caninum. However, in most studies, the intraperitoneal route was preferentially used to establish infection. Here, C57BL/6 mice were infected with N. caninum tachyzoites by the intragastric route, as it more closely resembles the natural route of infection through the gastrointestinal tract. The elicited T-cell mediated immune response was evaluated in the intestinal epithelium and mesenteric lymph nodes (MLN). Early upon the parasitic challenge, IL-12 production by conventional and plasmacytoid dendritic cells was increased in MLN. Accordingly, increased proportions and numbers of TCRαβ+CD8+IFN-γ+ lymphocytes were detected, not only in the intestinal epithelium and MLN, but also in the spleen of the infected mice. In this organ, IFN-γ-producing TCRαβ+CD4+ T cells were also found to increase in the infected mice, however later than CD8+ T cells. Interestingly, splenic and MLN CD4+CD25+ T cells sorted from infected mice presented a suppressive activity on in vitro T cell proliferation and cytokine production above that of control counterparts. These results altogether indicate that, by producing IFN-γ, TCRαβ+CD8+ cells contribute for local and systemic host protection in the earliest days upon infection established through the gastrointestinal tract. Nevertheless, they also provide substantial evidence for a parasite-driven reinforcement of T regulatory cell function which may contribute for parasite persistence in the host and might represent an additional barrier to overcome towards effective vaccination.

Toscana virus infection is endemic in Italy, but has also been documented in other Mediterranean countries. Our aim was to investigate the occurrence of Toscana virus (TOSV) meningitis in children and young adults in a metropolitan area in the north of Portugal. Cerebrospinal fluid samples from 308 patients with the diagnosis of meningitis and with negative bacterial culture were tested for enteroviruses and herpesviruseses by reverse transcription PCR. Those samples that proved negative for enterovirus and herpesvirus were tested for Toscana virus with a commercial reverse transcription nested PCR assay. In total, we investigated 106 samples, collected between May and September during the four-year period between 2002 and 2005 from patients younger than 30 years old. Toscana virus was the cause of meningitis in six (5.6%) of the cases, three children and three young adults. All had a benign course and self-limited disease. Since a first case report of TOSV infection 1985 and another in 1996, both in foreign tourists, these six cases of Toscana virus meningitis are, to our knowledge, the first diagnosed in Portuguese inhabitants, and they underline the need for more studies on the prevalence of this virus in Portugal.

Background: COVID-19 was declared a pandemic by the World Health Organization (WHO) on March 11st, 2020. Responses to this crisis integrated resource allocation for the increased amount of infected patients, while maintaining an adequate response to other severe and life-threatening diseases. Though cardiothoracic patients are at high risk for Covid-19 severe illness, postponing surgeries would translate in increased mortality and morbidity. We reviewed our practice during