Activation of microglial poly(ADP-ribose)-polymerase-1 by cholesterol breakdown products during neuroinflammation: a link between demyelination and neuronal damage

Multiple sclerosis (MS) is a chronic demyelinating disease in which it has only recently been suggested that damage to neuronal structures plays a key role. Here, we uncovered a link between the release of lipid breakdown products, found in the brain and cerebrospinal fluid (CSF) of MS patients as well as in experimental autoimmune encephalomyelitis, and neuronal damage mediated by microglial activation. The concentrations of the breakdown product 7-ketocholesterol detected in the CSF of MS patients were capable of inducing neuronal damage via the activation and migration of microglial cells in living brain tissue. 7-ketocholesterol rapidly entered the nucleus and activated poly(ADP-ribose)-polymerase (PARP)-1, followed by the expression of migration-regulating integrins CD11a and intercellular adhesion molecule 1. These findings reveal a novel mechanism linking demyelination and progressive neuronal damage, which might represent an underlying insidious process driving disease beyond a primary white matter phenomenon and rendering the microglial PARP-1 a possible antiinflammatory therapeutic target.     

Hippocampal lesions and discrimination performance of mice in the radial maze: sparing or impairment depending on the representational demands of the task

The effects of ibotenate hippocampal lesions on discrimination performance in an eight-arm radial maze were investigated in mice, using a three-stage paradigm in which the only parameter that varied among stages was the way the arms were presented. In the initial learning phase (stage 1), animals learned the valence or reward contingency associated with six (three positive and three negative) adjacent arms of the maze using a successive (go/no-go) discrimination procedure. In the first test phase (stage 2), the six arms were grouped into three pairs, so that on each trial, the subject was faced with a choice between two adjacent arms of opposite valence (concurrent two-choice discrimination). In the second test phase (stage 3), the subject was faced with all six arms simultaneously (six-choice discrimination). Hippocampal-lesioned mice acquired the initial learning phase at a near-normal rate but behaved as if they had learned nothing when challenged with the two-choice discriminations at stage 2. In contrast, they behaved normally when confronted with the six-choice discrimination at stage 3. Detailed examination of within- and between-stage performance suggests that hippocampal-lesioned mice perform as intact mice when presentation of the discriminanda encourages the storage and use of separate representations (i.e., in initial learning and six-choice discrimination testing), but that they fail in test situations that involve explicit comparisons between such separate representations (two-choice discriminations), hence requiring the use of relational representations.     

Safety and efficacy of switching psychiatric patients from a delayed-release to an extended-release formulation of divalproex sodium

This study evaluated the safety and efficacy of divalproex sodium extended-release (ER) when patients were switched from therapy with divalproex sodium delayed-release (DR) to divalproex sodium ER. This open-label, 7-day study included 55 patients with bipolar disorder, major depression, schizophrenia, schizoaffective disorder, Alzheimer's disease, dementia, or intermittent explosive disorder. Baseline plasma valproate concentrations were determined, and patients received their usual morning dose of divalproex sodium DR. At 9:00 p.m. the same day, they received divalproex sodium ER at a dose equal to their total daily dose of divalproex sodium DR. Valproate concentrations were monitored, and efficacy was measured with the Positive and Negative Syndrome Scale (PANSS). Side effects were assessed using the Udvalg for Kliniske Undersogelser (UKU) Side Effect Rating Scale. Valproate concentrations for 52 patients remained within the therapeutic range. Inpatient PANSS scores significantly improved from baseline to final evaluation on all subscales. For the combined inpatient and outpatient populations, a small but statistically significant improvement from baseline to final evaluation was seen for positive, general, and total PANSS subscale scores. At study's end, patients reported a significant decrease in the number and severity of adverse events; 54 of 55 patients elected to continue therapy with once-daily divalproex sodium ER. This study suggests that divalproex sodium ER is at least as effective as the DR formulation for treating patients with psychiatric illness and may be better tolerated. The ER formulation offers the advantage of once-daily dosing, which may help improve compliance.     

Guanidino N-substituted and N,N-disubstituted derivatives of the kappa-opioid antagonist GNTI

Derivatives of the highly selective kappa-opioid receptor antagonist GNTI (2a) have been prepared. Binding and functional studies conducted on cloned human opioid receptors expressed in Chinese hamster ovarian (CHO) cells suggested that adding a benzyl or a substituted benzyl group to the guanidino moiety led, in general, to a retention of high kappa-affinity and antagonist potency. Disubstitution of the guanidino moiety led to reduced kappa-selectivity.     

Detection of the breakage of pharmaceutical tablets in pneumatic transport

Pneumatic transport of pharmaceutical tablets is very convenient, compact and greatly reduces contamination. A potential problem, however, is the breakage of a significant fraction of the transported tablets, causing serious product quality problems. Since the flowrate of tablets transported through a given pneumatic transport line increases with gas velocity, lines are often operated at gas velocities slightly below the velocity at which tablets break. Minor changes in operating conditions can have a large effect on the impact resistance of tablets and on the observed tablet breakage rate. Therefore, maintaining a constant gas velocity is not sufficient to keep the tablet breakage rate below an acceptable level. The objective of the present study was to develop a reliable and non-invasive on-line method for the detection of tablet breakage. Pharmaceutical acetaminophen tablets were transported pneumatically in a 0.1 m diameter pipeline consisting of a 5 m vertical and a 4.0 m horizontal section made of either re-enforced PVC or steel. The pipeline flow regime was determined by visual observation through clear pipeline sections. Tablet breakage was quantified by screening tablet samples. Acoustic measurements were recorded at different locations along the pipeline. Analysis of the signals from microphones attached to the wall of the elbow and horizontal section provided a reliable detection of conditions leading to tablet breakage.     

Discovery, synthesis, and insecticidal activity of cycloaspeptide E

Several Penicillia and one Tricothecium strain produced a new, insecticidally active member of the cycloaspeptide family, with the proposed name cycloaspeptide E (1). The structure, which was determined on the basis of spectroscopic (NMR, UV, MS) data and Marfey amino acid analysis, was the tyrosine desoxy version of cycloaspeptide A (2). Two synthetic routes to compound 1 were developed: one a partial synthesis from 2 and the other a total synthesis from methyl alaninate hydrochloride. Cycloaspeptide E, the first member of this series not to contain a tyrosine moiety, is also the first to be reported with insecticidal activity.     

Multiple sclerosis: Heterology among early T cells and TG cells

Circulating early T cells and T_G cells were estimated simultaneously in 100 patients with multiple sclerosis and 21 controls. The results were analyzed from individual patients, from patients grouped according to disease activity, and from some patients studied longitudinally. Previously documented fluctuations in these two T cell populations were confirmed. By comparing the fluctuations and by examining the distribution of T_G cells in suspensions of isolated early and isolated late T cells, it was found that T_G cells are a T cell subpopulation distinct from early T cells.