An update of the molecular mechanisms underlying doxorubicin plus trastuzumab induced cardiotoxicity

Cardiotoxicity is a major side effect of the chemotherapeutic drug doxorubicin (Dox), which is further exacerbated when it is combined with trastuzumab, a standard care approach for Human Epidermal growth factor Receptor-type 2 (HER2) positive cancer patients. However, the molecular mechanisms of the underlying cardiotoxicity of this combination are still mostly elusive. Increased oxidative stress, impaired energetic substrate uses and topoisomerase IIB inhibition are among the biological processes proposed to explain Dox-induced cardiomyocyte dysfunction. Since cardiomyocytes express HER2, trastuzumab can also damage these cells by interfering with neuroregulin-1 signaling and mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)/Akt and focal adhesion kinase (FAK)-dependent pathways. Nevertheless, Dox and trastuzumab target other cardiac cell types, such as endothelial cells, fibroblasts, cardiac progenitor cells and leukocytes, which can contribute to the clinical cardiotoxicity observed. This review aims to summarize the current knowledge on the cardiac signaling pathways modulated by these two antineoplastic drugs highly used in the management of breast cancer, not only focusing on cardiomyocytes but also to broaden the knowledge of the potential impact on other cells found in the heart.

Nutrition Education in Portuguese Medical Students: Impact on the Attitudes and Knowledge

INTRODUCTION

Nutrition has been underrepresented in the curriculum of many medical schools and therefore physicians do not feel adequately prepared to provide dietary counselling. The aim of the present study is to determine the impact of a Nutrition and Metabolism curricular unit on nutrition attitudes, knowledge and confidence on future clinical practice of medical students.

MATERIAL AND METHODS

All the students enrolled in the curricular unit (2017/2018) were invited to complete a questionnaire assessing their nutritional knowledge and eating habits at the beginning and at the end of the semester (n = 310).

RESULTS

Initially, students reported good eating habits and nutrition knowledge. These aspects improved at the end of the study. Moreover, students reported that they felt more confident to do dietary counselling after intervention.

DISCUSSION

Most medical students answered affirmatively to all questions related with good habits or eating behaviours, and the acquisition of knowledge had an impact in specific attitudes. After the Nutrition and Metabolism classes the students felt able to provide dietary counselling in different clinical settings, but none of the students felt extremely confident about their competencies for dietary counselling. This can be due to the fact that the students involved were in the first year of the integrated master's degree in medicine, which is a preclinical year, and thus distant from the medical reality and from contact with patients.

CONCLUSION

Nutrition education can have a positive impact on attitudes and eating behaviours, knowledge and in the perception of competencies for dietary counselling.