Recombinant botulinum neurotoxin serotype A1 in vivo characterization.

Clinically used botulinum neurotoxins (BoNTs) are natural products of Clostridium botulinum. A novel, recombinant BoNT type A1 (rBoNT/A1; IPN10260) has been synthesized using the native amino acid sequence expressed in Escherichia coli and has previously been characterized in vitro and ex vivo. Here, we aimed to characterize rBoNT/A1 in vivo and evaluate its effects on skeletal muscle. The properties of rBoNT/A1 following single, intramuscular administration were evaluated in the mouse and rat digit abduction score (DAS) assays and compared with those of natural BoNT/A1 (nBoNT/A1). rBoNT/A1-injected tibialis anterior was assessed in the in situ muscle force test in rats. rBoNT/A1-injected gastrocnemius lateralis (GL) muscle was assessed in the compound muscle action potential (CMAP) test in rats. The rBoNT/A1-injected GL muscle was evaluated for muscle weight, volume, myofiber composition and immunohistochemical detection of cleaved SNAP25 (c-SNAP25). Results showed that rBoNT/A1 and nBoNT/A1 were equipotent and had similar onset and duration of action in both mouse and rat DAS assays. rBoNT/A1 caused a dose-dependent inhibition of muscle force and a rapid long-lasting reduction in CMAP amplitude that lasted for at least 30 days. Dose-dependent reductions in GL weight and volume and increases in myofiber atrophy were accompanied by immunohistochemical detection of c-SNAP25. Overall, rBoNT/A1 and nBoNT/A1 exhibited similar properties following intramuscular administration. rBoNT/A1 inhibited motoneurons neurotransmitter release, which was robust, long-lasting, and accompanied by cleavage of SNAP25. rBoNT/A1 is a useful tool molecule for comparison with current natural and future modified recombinant neurotoxins products.

Active compression versus standard anterior-posterior defibrillation for external cardioversion of atrial fibrillation: A prospective randomized study.

BACKGROUND: Electrical cardioversion is the first-line rhythm control therapy for symptomatic persistent atrial fibrillation (AF). Contemporary use of biphasic shock waveforms and anterior-posterior positioning of defibrillation electrodes have improved cardioversion efficacy; however, it remains unsuccessful in >10% of patients. OBJECTIVE: The purpose of this study was to assess the efficacy of applying active compression on defibrillation electrodes during AF cardioversion. METHODS: We performed a bicenter randomized study including patients referred for persistent AF cardioversion. Elective external cardioversion was performed by a standardized step-up protocol with increasing biphasic shock energy (50-100-150-200 J). Patients were randomly assigned to standard anterior-posterior defibrillation or to defibrillation with active compression applied over the anterior electrode. If sinus rhythm was not achieved at 200 J, a single crossover shock (200 J) was applied. Defibrillation threshold, total delivered energy, number of shocks, and success rate were compared between groups. RESULTS: We included 100 patients, 50 in each group. In the active compression group, defibrillation threshold was lower (103.1 ± 49.9 J vs 130.4 ± 47.7 J; P = .008), as well as total delivered energy (203 ± 173.3 J vs 309 ± 213.5 J; P = .0076) and number of shocks (2.2 ± 1.1 vs 2.9 ± 1.2; P = .0033), and cardioversion was more often successful (48 of 50 patients [96%] vs 42 of 50 patients [84%]; P = .0455) than that in the standard anterior-posterior group. Crossover from the compression group to the standard group was not successful (0 of 2 patients), whereas crossover from the standard group to the compression group was successful in 50% of patients (4 of 8). CONCLUSION: Active compression applied to the anterior defibrillation electrode is more effective for persistent AF cardioversion than standard anterior-posterior cardioversion, with lower defibrillation threshold and higher success rate.

Long-term treatment with standardized Ginkgo biloba extract (EGb 761) attenuates cognitive deficits and hippocampal neuron loss in a gerbil model of vascular dementia.

The standardized extract of Ginkgo biloba EGb 761 has been used to reduce cognitive dysfunction. The present study was designed to evaluate the effect of postischemic oral treatment with EGb 761 in a model of vascular dementia in gerbils. Daily oral posttreatment with EGb 761 led to a significant recovery of spatial memory assessed by the object location test, inhibited the decrease in plasma SOD activity and protected the hippocampal CA1 neurons, even when administered after the insult. These data provide further evidence for the therapeutic potential of EGb 761 in the treatment of vascular dementia.

BN82451 attenuates L-dopa-induced dyskinesia in 6-OHDA-lesioned rat model of Parkinson's disease.

The development of L-dopa-induced dyskinesia (LID) remains a major problem in the long-term treatment of Parkinson's disease (PD). This study aimed to assess the effect of the multitargeting molecule BN82451 on LID and to measure striatal mRNA expression of several genes in a rat model of PD. Rats were administered two unilateral injections of 6-OHDA in the striatum. After four weeks, the animals started a chronic daily treatment with increasing doses of L-dopa over a further four-week period. Over the course of L-dopa treatment, the rats developed abnormal involuntary movements (AIMs) classified as locomotive, axial, orolingual and forelimb dyskinesia. In animals rendered dyskinetic by L-dopa, administration of BN82451 at doses ranging from 1 to 10 mg/kg p.o. attenuated the severity of fully-established AIMs in a dose-related manner. This anti-dyskinetic effect could be achieved with lower doses of BN82451 administered sub chronically vs. acute single treatment. The improvement of AIMs is not due to a reduction in the general motor activity of dyskinetic rats. BN82451 treatment significantly reversed the overexpression of c-Fos, FosB and Arc mRNA associated with the dyskinesiogenic action of L-dopa. A significant correlation between the degree of overexpression of c-Fos, FosB and Arc mRNA and the dyskinesiogenic action of L-dopa was observed. The data demonstrate that BN82451 effectively attenuates LID and the associated molecular alterations in an animal model of PD and may represent a treatment option for managing dyskinesia.

Relationship between phosphodiesterase type 4 inhibition and anti-inflammatory activity of CI-1044 in rat airways.

The anti-inflammatory effects of CI-1044 and of the other selective PDE4 inhibitors rolipram and cilomilast were investigated in Brown-Norway (BN) rats, against lipopolysaccharide-induced tumor necrosis factor alpha (TNFalpha) production in whole blood and antigen-induced lung eosinophilia. In vitro, CI-1044 inhibited TNFalpha production with an IC(50) of 0.31 microm being equipotent to Cilomilast (IC(50) = 0.26 microm) and rolipram (IC(50) = 0.11 microm). Given orally, CI-1044 inhibited ex vivo TNFalpha production with an ED(50) value of 0.4 mg/kg after single administration, whereas rolipram (ED(50) = 1.4 mg/kg) and cilomilast (ED(50) = 1.6 mg/kg) were less potent. In the same ex vivo setting, but given repeatedly, CI-1044 led to an ED(50) of 0.5 mg/kg corresponding to a plasma concentration of 82.6 ng/mL (0.22 microm). In vivo, CI-1044 prevented TNFalpha release with an ED(50) of 1 mg/kg p.o. and inhibited ovalbumin-induced lung eosinophilia following single or repeated oral administration with an ED(50) of 3.25 and 4.8 mg/kg p.o., respectively, suggesting the absence of pharmacological tolerance. CI-1044 in this model was equipotent to rolipram (81% inhibition at 10 mg/kg) but better than cilomilast (25% inhibition at 10 mg/kg). Finally, CI-1044 (10 mg/kg) inhibited inflammatory cell recruitment with a long duration of action (up to 8 h) and was still active when given post-challenge. Our data show that CI-1044 is an orally active PDE4 inhibitor that may be used as an anti-inflammatory therapy in lung inflammatory diseases.

Oxaliplatin plus irinotecan and FU-FOL combination and pharmacokinetic analysis in advanced colorectal cancer patients.

This phase I-II trial was designed to assess the effect of irinotecan on oxaliplatin pharmacokinetics and to determine the MDT of both drugs when administered in combination. Treatment was repeated every 2 weeks. Pharmacokinetic studies were performed on cycle 1 and 2 to assess the best sequence and detect any interaction between the two drugs. Thirty-four patients with advanced colorectal cancer were enrolled; 28 of them (82%) had liver involvement. The main toxicities were neutropenia and delayed diarrhea; 5 patients (14%) experienced febrile neutropenia. Dose-limiting toxicity was experienced at levels 1/2/3/4/5 by 4/10, 1/6, 3/6, 3/8, and 3/4 patients, respectively. Fifteen patients responded (2 CR; 13 PR) for an ORR of 44%. No pharmacokinetic interactions between irinotecan and oxaliplatin were detected. The recommended dose for future phase II trials is oxaliplatin 85 mg/m and irinotecan 180 mg/m2 on day 1 combined with 5FU/leucovorin according to the de Gramont regimen at days 2 and 3. Twenty-nine percent of patients underwent secondary hepatectomy with curative intent, and two of them are long-term disease-free survivors. It would appear that the dose and schedule defined by this trial could be proposed as front-line therapy for advanced colorectal carcinoma to establish rapid disease control and to permit patients to proceed to surgery.