Effects of aripiprazole on alcohol intake in an animal model of high-alcohol drinking

AIMS: This study examined the effects of aripiprazole, a novel atypical antipsychotic drug with partial agonist properties at dopamine D2 receptors, on the voluntary limited access alcohol drinking of alcohol-preferring AA (Alko, Alcohol) rats. METHODS: AA rats were taught to drink 10% alcohol in a 4 h limited access paradigm. Effects of acute aripiprazole (0, 0.3, 1.0, and 3.0 mg/kg) on the limited access alcohol drinking were studied. In repeated treatment experiment, aripiprazole (0, 1.0, and 6.0 mg/kg) was administered once daily over five successive days. To reveal any effect by aripiprazole not selective for alcohol drinking, 0.025% saccharin solution was substituted for alcohol during the 4 h limited access, and acute treatments were repeated. The effects of aripiprazole on ambulatory locomotor activity were tested with doses that were used in the acute experiments. RESULTS: Acute aripiprazole at the doses of 0.3, 1.0, and 3.0 mg/kg had no effect on alcohol drinking. Repeated treatment with the aripiprazole dose of 6.0 mg/kg significantly diminished alcohol drinking at the 1 h time point. This dose had no effect on saccharin drinking when given acutely. Acute aripiprazole at the doses of 1.0, 3.0, and 6.0 mg/kg significantly suppressed locomotor activity. CONCLUSIONS: Aripiprazole decreased limited access alcohol drinking in AA rats, but only at a high dose that also strongly suppressed locomotor activity.     

Safety profile of plasmid/liposomes and virus vectors in clinical gene therapy

Despite of more than 500 gene therapy trials worldwide very little systematic safety information is available from gene therapy. Safety information was collected from 146 consecutive patients who participated in three randomized, controlled phase II gene therapy trials in cardiovascular diseases and malignant glioma using adenoviruses, plasmid/liposomes and retrovirus packaging cells. Total follow-up time of the patients was 78794 days which equals 1.5 years per patient. The main outcome measures were serious adverse events, other adverse events and changes in general laboratory parameters. Except fever and increases in CRP values plasmid/liposomes were safe and well tolerated. The incidence of serious adverse events in adenovirus-treated patients was 0.9 and 4.0/10000 patient days in cardiovascular and malignant glioma trials as compared to 0.5 and 2.1 in randomized control patients, respectively. Transient fever, leukopenia and increases in CRP and liver enzymes were detected in virus-treated patients. No deaths from side effects or no new cancers were associated with gene therapy. It is concluded that gene therapy, like any other therapy, is associated with side effects which depend on the administered vector, dose, and route of delivery and properties of the transgene. However, given the limitations of this study and length of the follow-up, the safety profile of gene therapy seems to be acceptable for the treatment of severe human diseases.     

THIP, a hypnotic and antinociceptive drug, enhances an extrasynaptic GABAA receptor-mediated conductance in mouse neocortex

THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) is a selective GABA(A) receptor agonist with a preference for delta-subunit containing GABA(A) receptors. THIP is currently being tested in human trials for its hypnotic effects, displaying advantageous tolerance and addiction properties. Since its cellular actions in the neocortex are uncertain, we studied the effects of THIP on neurons in slices of frontoparietal neocortex of 13- to 19-day-old (P13-19) mice. Using whole-cell patch-clamp recordings, we found that the clinically relevant THIP concentration of 1 muM induced a robust tonic GABA(A)-mediated current in layer 2/3 neurons. In comparison, only a minute tonic current was induced by mimicking in vivo endogenous GABA levels. Miniature IPSCs were not affected by 1 muM THIP suggesting an extrasynaptic site of action. The EC(50) for THIP was 44 muM. In accordance with the stronger expression of delta-containing receptors in superficial neocortical layers, THIP induced a 44% larger tonic current in layer 2/3 than in layer 5 neurons. Finally, monitoring spontaneously active neocortical neurons, THIP caused an overall depression of inhibitory activity, while enhancing excitatory activity prominently. Our studies suggest that THIP activates an extrasynaptic GABA(A) receptor-mediated conductance in the neocortex, which may alter the cortical network activity.     

Amplification of the urokinase gene and the sensitivity of prostate cancer cells to urokinase inhibitors

OBJECTIVES: To evaluate the frequency of the urokinase-type plasminogen activator (uPA) gene amplification and the sensitivity of prostate cancer cells to uPA inhibition, as we previously found one hormone-refractory prostate tumour with high-level amplification of the uPA (alias PLAU) gene, and also showed that a uPA inhibitor, amiloride, can effectively reduce the invasion potential of the PC-3 prostate cancer cell line. MATERIALS AND METHODS: Sixty-three locally recurrent hormone-refractory tumours and 78 hormone-refractory metastases from 29 patients who died from prostate cancer were analysed for uPA gene-copy number using fluorescence in situ hybridization. The Matrigel invasion assay was used to study the influence of uPA inhibitors on the invasive potential of prostate cancer cell lines. RESULTS: Of the locally recurrent hormone-refractory tumours, 21% had an increased copy number of uPA, but no high-level amplifications were found; 31% of the metastases had increased copy number and one high-level amplification of the uPA. Matrigel invasion assays with two specific uPA inhibitors, B428 and p-aminobenzamidine, showed that invasion of a prostate cancer cell line containing uPA gene amplification was inhibited by these small-molecule uPA inhibitors, while invasion of prostate cell lines without uPA gene amplification were not. CONCLUSION: These results suggest that selective inhibition of the uPA pathway in individuals whose tumours contain uPA gene amplification may provide therapeutic benefit.     

Catecholaminergic polymorphic ventricular tachycardia: recent mechanistic insights

Cardiac excitation-contraction coupling occurs by a calcium ion-mediated mechanism in which the signal of action potential is converted into Ca2+ influx into the cardiomyocytes through the sarcolemmal L-type calcium channels. This is followed by Ca2+-induced release of additional Ca2+ ions from the lumen of the sarcoplasmic reticulum into the cytosol via type 2 ryanodine receptors (RyR2). RyR2 channels form large complexes with additional regulatory proteins, including FKBP12.6 and calsequestrin 2 (CASQ2). Catecholamines, released into the body fluids during emotional or physical stress, activate Ca2+-induced Ca2+ release by protein kinase A-mediated phosphorylation of RyR2. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an insidious, early-onset and highly malignant, inherited disorder characterized by effort-induced ventricular arrhythmias in the absence of structural alterations of the heart. At least some cases of sudden, unexplained death in young individuals may be ascribed to CPVT. Mutations of the RyR2 gene cause autosomal dominant CPVT, while mutations of the CASQ2 gene may cause an autosomal recessive or dominant form of CPVT. The steps of the molecular pathogenesis of CPVT are not entirely clear, but inappropriate "leakiness" of RyR2 channels is thought to play a role; the underlying mechanisms may involve an increase in the basal activity of the RyR2 channel, alterations in its phosphorylation status, a defective interaction of RyR2 with other molecules or ions, such as FKBP12.6, CASQ2, or Mg2+, or its abnormal activation by extra- or intraluminal Ca2+ ions. Beta-adrenergic antagonists have proven to be of value in prevention of arrhythmias in CPVT patients, but occasional treatment failures call for alternative measures. There is great interest at present for the development of novel antiarrhythmic drugs for CPVT, as the same approaches may be applied for treatment of more common forms of life-threatening arrhythmias, such as those arising during ischemia and heart failure.     

BCR-ABL kinase domain mutation analysis in chronic myeloid leukemia patients treated with tyrosine kinase inhibitors: recommendations from an expert panel on behalf of European LeukemiaNet

Mutations in the Bcr-Abl kinase domain may cause, or contribute to, resistance to tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia patients. Recommendations aimed to rationalize the use of BCR-ABL mutation testing in chronic myeloid leukemia have been compiled by a panel of experts appointed by the European LeukemiaNet (ELN) and European Treatment and Outcome Study and are here reported. Based on a critical review of the literature and, whenever necessary, on panelists' experience, key issues were identified and discussed concerning: (1) when to perform mutation analysis, (2) how to perform it, and (3) how to translate results into clinical practice. In chronic phase patients receiving imatinib first-line, mutation analysis is recommended only in case of failure or suboptimal response according to the ELN criteria. In imatinib-resistant patients receiving an alternative TKI, mutation analysis is recommended in case of hematologic or cytogenetic failure as provisionally defined by the ELN. The recommended methodology is direct sequencing, although it may be preceded by screening with other techniques, such as denaturing-high performance liquid chromatography. In all the cases outlined within this abstract, a positive result is an indication for therapeutic change. Some specific mutations weigh on TKI selection.     

Long-term results of surgery for lumbar spinal stenosis: a randomised controlled trial

We randomised a total of 94 patients with long-standing moderate lumbar spinal stenosis (LSS) into a surgical group and a non-operative group, with 50 and 44 patients, respectively. The operative treatment comprised undercutting laminectomy of stenotic segments, augmented with transpedicular-instrumented fusion in suspected lumbar instability. The primary outcome was the Oswestry disability index (ODI), and the other main outcomes included assessments of leg and back pain and self-reported walking ability, all based on questionnaire data from 85 patients at the 6-year follow-up. At the 6-year follow-up, the mean difference in ODI in favour of surgery was 9.5 (95% confidence interval 0.9–18.1, P-value for global difference 0.006), whereas the intensity of leg or back pain did not differ between the two treatment groups any longer. Walking ability did not differ between the treatment groups at any time. Decompressive surgery of LSS provided modest but consistent improvement in functional ability, surpassing that obtained after non-operative measures.     

Intra- and inter-observer reliability using a noninvasive ultrasound cardiac output monitor in healthy anesthetized children

Background: Accurate and reliable evaluation of cardiac index (CI) in critically ill pediatric patients can optimize their management. Although validated, noninvasive ultrasound measurement techniques have been previously shown to be unreliable because of observer variability. Objective: To confirm intra‐ and inter‐observer reliability when using the noninvasive USCOM^® in healthy anesthetized children. Methods: Prospective observational study at the Children’s Hospital of Eastern Ontario, Ottawa, included newborns to 12 years of age undergoing elective surgery or magnetic resonance imaging. The USCOM^® was used to assess CI via aortic flow with a trans‐sternal approach. Two trained observers were responsible for taking two measurements of CI each at steady state in randomized succession after stable depth of anesthesia was achieved. Results: Fifty‐nine patients were included. Forty‐seven (80%) were between 3 and 7 years old, with 57% male. The mean difference ± sd for repeat CI measurements by each of two observers was 0.11 ± 0.47 and 0.05 ± 0.65 l·min^?1·m^?2, respectively. Intra‐observer reliability for these repeat measurements by each observer determined by Lin’s concordance correlation coefficient was 0.92 and 0.85, respectively. The mean difference ± sd between observers was 0.16 ± 0.59 l·min^?1·m^?2, and Lin’s concordance correlation coefficient was 0.87. The two observers subjectively rated measurements as ‘Difficult’ or ‘Very difficult’ only 14% (16/118) and 3% (4/118) of the time, respectively. No adverse events were reported. Conclusion: This study confirms that the USCOM^® is relatively easy to use and reliable in healthy children when operated by trained users.