Drug delivery nanosystems targeted to hepatic ischemia and reperfusion injury.

Hepatic ischemia and reperfusion injury (IRI) is an acute inflammatory process that results from surgical interventions, such as liver resection surgery or transplantation, or hemorrhagic shock. This pathology has become a severe clinical issue, due to the increasing incidence of hepatic cancer and the high number of liver transplants. So far, an effective treatment has not been implemented in the clinic. Despite its importance, hepatic IRI has not attracted much interest as an inflammatory disease, and only a few reviews addressed it from a therapeutic perspective with drug delivery nanosystems. In the last decades, drug delivery nanosystems have proved to be a major asset in therapy because of their ability to optimize drug delivery, either by passive or active targeting. Passive targeting is achieved through the enhanced permeability and retention (EPR) effect, a main feature in inflammation that allows the accumulation of the nanocarriers in inflammation sites, enabling a higher efficacy of treatment than conventional therapies. These systems also can be actively targeted to specific compounds, such as inflammatory markers and overexpressed receptors in immune system intermediaries, allowing an even more specialized therapy that have already showed encouraging results. In this manuscript, we review drug delivery nanosystems designed for hepatic IRI treatment, addressing their current state in clinical trials, discussing the main hurdles that hinder their successful translation to the market and providing some suggestions that could potentially advance their clinical translation.

Left ventricular non-compaction: a new mutation predisposing to reverse remodeling?

Left ventricular non-compaction (LVNC) is a rare disorder of endomyocardial morphogenesis that results in multiple trabeculations and deep intertrabecular recesses filled with direct blood flow from the left ventricular cavity. LVNC is attracting increasing interest as a model for the study of cardiomyopathies, since it is a genetically heterogeneous disorder which varies greatly in clinical presentation and age of onset. The authors present the case of a young black male with progressive congestive heart failure of 2-3 years' evolution. The investigation, which included transthoracic echocardiography (contrast and 3D), transesophageal echocardiography and cardiac magnetic resonance imaging, showed LVNC and severe aortic regurgitation, with severe left ventricular systolic dysfunction. The family history was suggestive of genetically transmitted disease and genetic study of the TAZ gene at locus Xq28 identified the mutation p.Phe128Ser (c.383T>C), the first description of this mutation in a patient with LVNC. The patient underwent aortic valve replacement, with excellent clinical evolution, regression of left ventricular dimensions and global systolic functio Aortic regurgitation (not related to LVNC) was the determining factor in the clinical expression. However, the excellent reverse remodeling that occurred after surgery highlights the heterogeneity of myocardial behavior in LVNC patients.

A novel BCR-ABL1 mutation in a patient with Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) represents the most common genetic subtype of adult ALL (20%-30%) and accounts for approximately 50% of all cases in the elderly. It has been considered the subgroup of ALL with the worst outcome. The introduction of tyrosine kinase inhibitors (TKIs) allows complete hematologic remission virtually in all patients, with improved disease-free survival and overall survival. Nevertheless, the emergence of resistant mutations in BCR-ABL1 may require different TKI strategies to overcome the patient's resistance and disease relapse. Here, we report a Ph+B-ALL case with persistent minimal residual disease (MRD) after treatment with dasatinib. The patient expressed the P190BCR-ABL1 isoform and a novel BCR-ABL1 mutation, p.Y440C. The latter is in the C-terminal lobe of the kinase domain, which likely induces deviations in the protein structure and activity and destabilizes its inactive conformation. The treatment was substituted by bosutinib, which binds to the active conformation of the protein, prior to allogeneic bone marrow transplant to overcome the lack of a complete response to dasatinib. These findings strengthen the importance of BCR-ABL1 mutational screening in Ph+ patients, particularly for those who do not achieve complete molecular remission.

Early transcriptional response of Saccharomyces cerevisiae to stress imposed by the herbicide 2,4-dichlorophenoxyacetic acid.

The global gene transcription pattern of the eukaryotic experimental model Saccharomyces cerevisiae in response to sudden aggression with the widely used herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was analysed. Under acute stress, 14% of the yeast transcripts suffered a greater than twofold change. The yeastract database was used to predict the transcription factors mediating the response registered in this microarray analysis. Most of the up-regulated genes in response to 2,4-D are known targets of Msn2p, Msn4p, Yap1p, Pdr1p, Pdr3p, Stp1p, Stp2p and Rpn4p. The major regulator of ribosomal protein genes, Sfp1p, is known to control 60% of the down-regulated genes, in particular many involved in the transcriptional and translational machinery and in cell division. The yeast response to the herbicide includes the increased expression of genes involved in the oxidative stress response, the recovery or degradation of damaged proteins, cell wall remodelling and multiple drug resistance. Although the protective role of TPO1 and PDR5 genes was confirmed, the majority of the responsive genes encoding multidrug resistance do not confer resistance to 2,4-D. The increased expression of genes involved in alternative carbon and nitrogen source metabolism, fatty acid beta-oxidation and autophagy was also registered, suggesting that acute herbicide stress leads to nutrient limitation.