Serratia marcescens cytotoxin was purified to homogeneity by ionexchange chromatography on a DEAE Sepharose Fast Flow column, followed by gel filtration chromatography on a Sephadex G100 column. The molecular mass of the cytotoxin was estimated to be about 50 kDa. Some biological properties of the cytotoxin were analyzed and compared with well-characterized toxins, such as VT1, VT2 and CNF from Escherichia coli and hemolysin produced by S. marcescens. The sensitivity of the cell lines CHO, HeLa, HEp-2, Vero, BHK-21, MA 104 and J774 to the cytotoxin was determined by the cell viability assay using neutral red. CHO and HEp-2 were highly sensitive, with massive cellular death after 1 h of treatment, followed by BHK-21, HeLa, Vero and J774 cells, while MA 104 was insensitive to the toxin. Cytotoxin induced morphological changes such as cell rounding with cytoplasmic retraction and nuclear compactation which were evident 15 min after the addition of cytotoxin. The cytotoxic assays show that 15 min of treatment with the cytotoxin induced irreversible intoxication of the cells, determined by loss of cell viability. Concentrations of 2 CD 50 (0.56 µg/ml) of purified cytotoxin did not present any hemolytic activity, showing that the cytotoxin is distinct from S. marcescens hemolysin. Antisera prepared against S. marcescens cytotoxin did not neutralize the cytotoxic activity of VT1, VT2 or CNF toxin, indicating that these toxins do not share antigenic determinants with cytotoxin. Moreover, we did not detect gene sequences for any of these toxins in S. marcescens by PCR assay. These results suggest that S. marcescens cytotoxin is not related to any of these toxins from E. coli. Correspondence

No abstract

This paper presents the description and analysis of a didactic experience involving the participation of a university and a community school, developed as part of the National Science and Technology Week, at a public university in northeastern Brazil. For this purpose, the use of learning station rotation enabled innovation in the teaching of physiology integrated with biochemistry and health education contents. The didactic approach consisted of creating a learning circuit comprising seven stations. The central theme of the stations emphasized physiology, with specific foci on biochemistry and cardiorespiratory and endocrine health. Each station provided unique activities related to the central theme, including a station concerning digital technology in physiology. The school students were divided into small groups (6 or 7 people) that rotated through the stations, with a total of 81 students visiting each station. A qualitative assessment was performed using a Likert-scale questionnaire to measure the level of satisfaction of the students. It was found that this didactic approach increased the receptivity of the students to the contents, facilitated student-teacher dialogue, and provided an excellent tool for establishing an interface between the university and the community school. Overall, 76.5% of the students rated the activity as excellent.

<p class="MsoNormal" style="margin-bottom: 0.0001pt; text-align: justify;"><span style="font-size: 8.0pt; mso-ascii-font-family: Calibri; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri;">As alterações metabólicas necessárias para o desenvolvimento da gestação podem desencadear processos patológicos, como o diabetes melito gestacional (DMG). Essa condição é um preditor de risco para o estabelecimento do diabetes melito tipo 2 (DM2), uma morbidade associada ao grande comprometimento da qualidade de vida. A adiponectina (AdipoQ), hormônio produzido pelos adipócitos, surge como um importante sinalizador de risco para evolução do DMG em DM tipo 2, em mulheres com histórico do DMG em alguma de suas gestações. A AdipoQ é encontrada no plasma sanguíneo em frações de diferentes densidades. Baixa concentração nos níveis de AdipoQ representa grande risco para o desenvolvimento do DM2 até 10 anos após o parto. A atividade física é uma ferramenta no tratamento do DM2, promovendo alterações agudas e crônicas que podem diminuir a glicemia, ou mesmo permitir o controle sem medicamento. Nesse contexto, foi investigada a atividade física como possível fator preventivo na medição dos níveis de AdipoQ, para influenciar no risco de estabelecimento do DM2 no pós-parto, em mulheres com diagnóstico do DMG.</span></p>

A Escherichia coli é uma bactéria gram-negativa presente no intestino de aves e mamíferos, geralmente sem causar danos ao hospedeiro (Croxen et al., 2013).