Involvement of hippocampal CA3 KATP channels in contextual memory

This paper evaluates the involvement of hippocampal ATP-sensitive potassium channels (K_ATP) in learning and memory. After confirming expression of the Kir6.2 subunit in the CA3 region of C57BL/6J mice, we performed intra-hippocampal pharmacological injections of specific openers and blockers of K_ATP channels. The opener diazoxide, the blocker tolbutamide, or a mixture of both, were bilaterally injected in the CA3 region before we subjected the animals to a fear conditioning paradigm. Diazoxide strongly impaired contextual memory of mice at both doses tested. This impairment was specifically reversed by co-injecting the blocker tolbutamide. Moreover, we studied the mnemonic abilities of mice deleted for the Kir6.2 subunit. These mice were backcrossed to C57BL/6J mice and tested in two learning paradigms. We found a significant impairment of contextual and tone memories in the Kir6.2 knock-out mice when compared with heterozygous or wild-type animals. Furthermore, these animals were also slightly impaired in a spatial version of the Morris water maze task. Our data suggest a specific involvement of hippocampal K_ATP Kir6.2/SUR1 channels in memory processes.     

Streptococcus canis infections in humans: retrospective study of 54 patients

This 5-year retrospective study reports 54 patients with infection, caused by Streptococcus canis, a pyogenic Lancefield group G streptococcus initially isolated from various animal sources. During 1997-2002, Streptococcus canis accounted for 1% of all streptococci isolated. The clinical signs, outcome and bacteriological characteristics were reviewed. All except eight were symptomatic. Clinical manifestations were: soft tissue infection (n=35), bacteremia (n=5), urinary infection (n=3), bone infection (n=2) and pneumonia (n=1). The course was favorable in 52 cases while two died from sepsis. Cultures were often polymicrobial (n=42, 77.8%) apart from hemocultures. The isolates were sensitive to most antibiotics. Presence of the bacteria did not always signify infection owing to the possible occurrence of colonization. The frequency of S. canis infections is rare and likely underestimated owing to the fact that streptococci are sought only on the basis of the Lancefield classification. The search for S. canis is recommended whenever patients present with symptoms evocative of exposure to a potentially contaminated animal.     

Synthesis of new dipyrrolo- and furopyrrolopyrazinones related to tripentones and their biological evaluation as potential kinases (CDKs1-5, GSK-3) inhibitors

We herein describe the synthesis of novel dipyrrolo- and furopyrrolopyrazinones related to highly cytotoxic tripentones and to their oximes. The synthetic pathway involved in particular a Curtius rearrangement and a subsequent cyclisation into the title pyrazinones. The biological evaluation towards various cyclin-dependent kinases (CDKs1-5, GSK-3) highlighted a weak inhibitory activity for the oximes whose SAR was studied by a molecular modeling study.     

Changes in local and network brain activity after stereotactic thermocoagulation in patients with drug-resistant epilepsy

Objective

Stereoelectroencephalography-guided radiofrequency thermocoagulation (SEEG-guided RF-TC) aims to reduce seizure frequency by modifying epileptogenic networks through local thermocoagulative lesions. Although RF-TC is hypothesized to functionally modify brain networks, reports of changes in functional connectivity (FC) following the procedure are missing. We evaluated, by means of SEEG recordings, whether variation in brain activity after RF-TC is related to clinical outcome.

Methods

Interictal SEEG recordings from 33 patients with drug-resistant epilepsy (DRE) were analyzed. Therapeutic response was defined as a >50% reduction in seizure frequency for at least 1 month following RF-TC. Local (power spectral density [PSD]) and FC changes were evaluated in 3-min segments recorded shortly before (baseline), shortly after, and 15 min after RF-TC. The PSD and FC strength values after thermocoagulation were compared with baseline as well as between the responder and nonresponder groups.

Results

In responders, we found a significant reduction in PSD after RF-TC in channels that were thermocoagulated for all frequency bands (p = .007 for broad, delta and theta, p <.001 for alpha and beta bands). However, we did not observe such PSD decrease in nonresponders. At the network level, nonresponders displayed a significant FC increase in all frequency bands except theta (broad, delta, beta band: p <.001; alpha band: p <.01), although responders showed a significant FC decrease in delta (p <.001) and alpha bands (p <.05). Nonresponders showed stronger FC changes with respect to responders exclusively in TC channels (broad, alpha, theta, beta: p >.05; delta: p = .001).

Significance

Thermocoagulation induces both local and network-related (FC) changes in electrical brain activity of patients with DRE lasting for at least 15 min. This study demonstrates that the observed short-term modifications in brain network and local activity significantly differ between responders and nonresponders and opens new perspectives for studying the longer-lasting FC changes after RF-TC.     

Bleeding risk with concurrent use of anticoagulants and ibrutinib: A population-based nested case-control study

Data regarding the safety of co-administration of ibrutinib with anticoagulants in real-life settings are scarce. Using a nationwide database, we conducted a nested case-control study in a cohort of new users of ibrutinib to assess the risk of clinically relevant bleeding (CRB) associated with anticoagulation. Cases were patients with a diagnosis of CRB, defined as hospitalization with a diagnosis of bleeding. The date of CRB constituted the index date. Up to four controls were matched on sex, age at index date and duration of follow-up. The risk of CRB associated with anticoagulation in patients receiving ibrutinib was estimated using conditional logistic regression models, providing odds ratios (OR) adjusted for risk factors of bleeding. Among 614 cases and 2407 matched controls, the risk of CRB was significantly higher in patients receiving both ibrutinib and anticoagulants (adjusted OR [aOR] 2.54, confidence interval [CI] 95% [1.94; 3.32]). When considering anticoagulant class, aOR was 1.99 (CI 95% [1.19; 3.33]) for VKA, 2.48 (CI 95% [1.76; 3.47]) for direct oral anticoagulants and 3.40 (CI 95% [2.01; 5.75]) for parenteral anticoagulants. In conclusion, this study found a 2.5-fold increased risk of CRB in patients receiving both ibrutinib and anticoagulants in real-life settings, and similar aOR among oral anticoagulants.