A phase II study of the combination of endocrine treatment and bortezomib in patients with endocrine-resistant metastatic breast cancer

The majority of patients with hormone receptor-positive metastatic breast cancer die from disease progression despite different types of anti-hormonal treatments. Preclinical studies have indicated that resistance to anti-hormonal therapies may be the result of an activated NF-κB signalling pathway in breast cancer. Bortezomib is a proteasome inhibitor that blocks the NF-κB pathway. Recent pharmacodynamic and pharmaco-kinetic xenograft studies have shown that drug exposure may be a crucial factor for the efficacy of bortezomib in solid tumours. The aim was to investigate whether the addition of bortezomib to anti-hormonal therapy would result in regained antitumour activity in patients with progressive and measurable disease being treated with an endocrine agent. Clinical benefit was defined as patients obtaining stable disease, partial response or complete response after 2 cycles, lasting for at least another five weeks. Bortezomib was administered on days 1, 8, 15 and 22 of a 5-week regimen (1.6?mg/m2). Eight patients received an aromatase inhibitor and bortezomib, while one received tamoxifen and bortezomib. There were 3 grade 3 gastrointestinal toxicities. Median time to treatment failure was 69 days (range, 35-140). Two out of the 9 patients had stable disease for more than 10 weeks. Despite an effective target inhibition, suggested in peripheral blood mononuclear cells and available tumour samples, no objective antitumour responses were observed. Addition of a proteasome inhibitor to anti-hormonal therapy resulted in a clinical benefit rate of 22% in a limited number of patients with endocrine resistant and progressive metastatic breast cancer. The demonstrated proteasome inhibition in tumour tissue provides evidence that the lack of clinical responses is not attributed to deficient drug exposure.     

The relationship between behavior acquisition and persistence abilities: Involvement of adult hippocampal neurogenesis

The influence of the learning process on the persistence of the newly acquired behavior is relevant both for our knowledge of the learning/memory mechanisms and for the educational policy. However, it is unclear whether during an operant conditioning process with a continuous reinforcement paradigm, individual differences in acquisition are also associated to differences in persistence of the acquired behavior. In parallel, adult neurogenesis has been implicated in spatial learning and memory, but the specific role of the immature neurons born in the adult brain is not well known for this process. We have addressed both questions by analyzing the relationship between water maze task acquisition scores, the persistence of the acquired behavior, and the size of the different subpopulations of immature neurons in the adult murine hippocampus. We have found that task acquisition and persistence rates were negatively correlated: the faster the animals find the water maze platform at the end of acquisition stage, the less they persist in searching for it at the learned position in a subsequent non‐reinforced trial; accordingly, the correlation in the number of some new neurons' subpopulations and the acquisition rate is negative while with persistence in acquired behavior is positive. These findings reveal an unexpected relationship between the efficiency to learn a task and the persistence of the new behavior after a non‐reinforcement paradigm, and suggest that the immature neurons might be involved in different roles in acquisition and persistence/extinction of a learning task. © 2016 Wiley Periodicals, Inc.     

Improving the analysis of routine outcome measurement data: what a Bayesian approach can do for you

Since recent decades, clinicians offering interventions against mental problems must systematically collect data on how clients change over time. Since these data typically contain measurement error, statistical tests have been developed which should disentangle true changes from random error. These statistical tests can be subdivided into two types: classical tests and Bayesian tests. Over the past, there has been much confusion among analysts regarding the questions that are answered by each of these tests. In this paper we discuss each type of test in detail and explain which questions are, and which are not, answered by each of the types of tests. We then apply a test of each type on an empirical data set and compare the results. Copyright © 2015 John Wiley & Sons, Ltd     

Increased PLA2 activity in individuals at ultra-high risk for psychosis

European Archives of Psychiatry and Clinical Neuroscience - Phospholipase A2 is the main enzyme in the metabolism of membrane phospholipids. It comprises a family of enzymes divided into iPLA2,...     

The NMDA-receptor antagonist MK-801 selectively disrupts reversal learning in rats

We tested the hypothesis that inhibition of NMDA-receptors in rats would lead to a selective impairment of reversal learning in a serial reversal task in the Skinner box. Low doses of MK-801 (0.025 and 0.05 mg/kg) did not affect acquisition of the two-lever discrimination, but impaired performance during the first reversal more than during the third reversal. Similar effects were observed during the series of extinction sessions. The high dose (0.1 mg/kg) completely inhibited reversal and extinction learning, as the rats perseverated in pressing the previously rewarded lever(s). We conclude that NMDA receptor blockade leads to a selective impairment in cognitive flexibility, and shows some similarity to transient inactivation of the medial prefrontal cortex in this respect.