P53 and Rb Aberrations in Small Cell Lung Cancer (SCLC): From Molecular Mechanisms to Therapeutic Modulation.

The genes coding for the tumor suppressors p53 and retinoblastoma (Rb) are inactivated in the vast majority of small cell lung cancer (SCLC) tumors. Data support the notion that these two deleterious genetic events represent the initial steps in the development of SCLC, making them essential for a lung epithelial cell to progress toward the acquisition of a malignant phenotype. With the loss of TP53 and RB1, their broad tumor suppressive functions are eliminated and a normal cell is able to proliferate indefinitely, escape entering into cellular senescence, and evade death, no matter the damage it has experienced. Within this setting, lung epithelial cells accumulate further oncogenic mutations and are well on their way to becoming SCLC cells. Understanding the molecular mechanisms of these genetic lesions and their effects within lung epithelial cells is of paramount importance, in order to tackle this aggressive and deadly lung cancer. The present review summarizes the current knowledge on p53 and Rb aberrations, their biological significance, and their prospective therapeutic potential, highlighting completed and ongoing clinical trials with agents that target downstream pathways.

Angiotensin-Converting Enzyme 2 (ACE2) Signaling in Pulmonary Arterial Hypertension: Underpinning Mechanisms and Potential Targeting Strategies.

Pulmonary arterial hypertension (PAH) is a debilitating progressive disease characterized by excessive pulmonary vasoconstriction and abnormal vascular remodeling processes that lead to right-ventricular heart failure and, ultimately, death. Although our understanding of its pathophysiology has advanced and several treatment modalities are currently available for the management of PAH patients, none are curative and the prognosis remains poor. Therefore, further research is required to decipher the molecular mechanisms associated with PAH. Angiotensin-converting enzyme 2 (ACE2) plays an important role through its vasoprotective functions in cardiopulmonary homeostasis, and accumulating preclinical and clinical evidence shows that the upregulation of the ACE2/Angiotensin-(1-7)/MAS1 proto-oncogene, G protein-coupled receptor (Mas 1 receptor) signaling axis is implicated in the pathophysiology of PAH. Herein, we highlight the molecular mechanisms of ACE2 signaling in PAH and discuss its potential as a therapeutic target.

The European Registry on Obstetric Antiphospholipid Syndrome (EUROAPS): A survey of 1000 consecutive cases.

AIM: To analyse the clinical features, laboratory data and foetal-maternal outcomes, and follow them up on a cohort of 1000 women with obstetric antiphospholipid syndrome (OAPS). METHODS: The European Registry of OAPS became a registry within the framework of the European Forum on Antiphospholipid Antibody projects and was placed on a website in June 2010. Thirty hospitals throughout Europe have collaborated to carry out this registry. Cases with obstetric complaints related to antiphospholipid antibodies (aPL) who tested positive for aPL at least twice were included prospectively and retrospectively. The seven-year survey results are reported. RESULTS: 1000 women with 3553 episodes were included of which 2553 were historical and 1000 were latest episodes. All cases fulfilled the Sydney classification criteria. According to the laboratory categories, 292 (29.2%) were in category I, 357 (35.7%) in IIa, 224 (22.4%) in IIb and 127 (12.7%) in IIc. Miscarriages were the most prevalent clinical manifestation in 386 cases (38.6%). Moreover, the presence of early preeclampsia (PE) and early foetal growth restriction (FGR) appeared in 181 (18.1%) and 161 (16.1%), respectively. In this series, 448 (44.8%) women received the recommended OAPS treatment. Patients with recommended treatment had a good live-birth rate (85%), but worse results (72.4%) were obtained in patients with any treatment (low-dose aspirin (LDA) or low-molecular-weight heparin (LMWH) not on recommended schedule, while patients with no treatment showed a poor birth rate (49.6%). CONCLUSION: In this series, recurrent miscarriage is the most frequent poor outcome. To avoid false-negative diagnoses, all laboratory category subsets were needed. OAPS cases have very good foetal-maternal outcomes when treated. Results suggest that we were able to improve our clinical practice to offer better treatment and outcomes to OAPS patients.

Heteroresistance to meropenem in carbapenem-susceptible Acinetobacter baumannii.

The characteristics of carbapenem heteroresistance were studied in 14 apparently carbapenem-susceptible Acinetobacter baumannii isolates. The MICs for carbapenems were determined, and the isolates were genotyped by pulsed-field gel electrophoresis (PFGE) and sequence typing (ST). Population analysis, testing of the stability of the heteroresistant subpopulations, and time-killing assays were performed. The agar dilution MICs of both imipenem and meropenem for the native isolates ranged from 0.25 to 4 mg/liter. The isolates belonged to nine PFGE types and exhibited seven ST allelic profiles. Population analysis revealed subpopulations that grew in the presence of imipenem at concentrations of up to 8 mg/liter and meropenem at concentrations of up to 32 mg/liter. The meropenem-heteroresistant subpopulations of 11 isolates exhibited stable resistance with MICs that ranged from 16 to >32 mg/liter; their PFGE profiles were identical to those of the native isolates. Time-kill assays with meropenem revealed less pronounced killing for 10 isolates. These findings indicate that meropenem pressure can produce meropenem-heteroresistant subpopulations that might subsequently select for highly resistant strains.