Autoradiographic analysis of mouse brain kinin B1 and B2 receptors after closed head trauma and ability of Anatibant mesylate to cross the blood-brain barrier

The potent non-peptide B2 receptor (R) antagonist, Anatibant mesylate (Ms) (LF 16-0687 Ms), reduces brain edema and improves neurological function recovery in various focal and diffuse models of traumatic brain injury in rodents. In the present study, alteration of kinin B1 and B2R after closed head trauma (CHT) and in vivo binding properties of Anatibant Ms (3 mg/kg, s.c.) injected 30 min after CHT were studied in mice by autoradiography using the radioligands [125I]HPP-Hoe 140 (B2R), and [125I]HPP-des-Arg10-Hoe 140 (B1R). Whereas B1R is barely detected in most brain regions, B2R is extensively distributed, displaying the highest densities in the hindbrain. CHT was associated with a slight increase of B1R and a decrease of B2R (10-50%) in several brain regions. Anatibant Ms (Ki = 22 pM) displaced the B2R radioligand from its binding sites in several areas of the forebrain, basal ganglia and hindbrain. Displacement was achieved in 1 h and persisted at 4 h post-injection. The inhibition did not exceed 50% of the total specific binding in non-injured mice. After CHT, the displacement by Anatibant Ms was higher and almost complete in the cortex, caudate putamen, thalamus, hippocampus, medial geniculate nucleus, ventral tegmental area, and raphe. Evans blue extravasation in brain tissue at 4 h after CHT was abolished by Anatibant Ms. It appeared that Anatibant Ms penetrated into the brain in sufficient amounts, particularly after disruption of the blood-brain barrier, to account for its B2R-mediated neuro- and vascular protective effects. The diminished binding of B2R after CHT may reflect the occupancy or internalization of B2R following the endogenous production of bradykinin (BK).     

Posterior Approach for Laparoscopic Pancreaticoduodenectomy to Prevent Replaced Hepatic Artery Injury

Background

Laparoscopic pancreaticoduodenectomy (PD) has become more popular despite its complexity and tendency for higher morbidity.1 Replaced right hepatic artery (RRHA) and replaced common hepatic artery (RCHA), both originating from the superior mesenteric artery (SMA), are the most significant and relatively common vascular anomalies in patients undergoing PD, occurring in 8.6–21 and 0.4–4.5 % of cases, respectively.2 ^, 3 An inadvertent injury to theses arteries may result in an intra- or postoperative bleeding, hepatic or bile duct ischemia, and consequent leakage or delayed stricture in the bilioenteric anastomosis.2 ^– 4 Therefore, preservation of these aberrant hepatic arteries is essential unless their resection is oncologically indicated.2 We describe a posterior approach that can be advantageous in laparoscopic PD for patients with a RRHA or RCHA.

Methods

The posterior approach was used in 81 laparoscopic PDs at the Institute Mutualiste Montsouris between 1994 and 2012.5 In brief, retropancreatic dissection is performed to complete kocherization and expose the posterolateral aspect of the SMA. The origin of the RRHA or RCHA can then be identified and dissected. After division of the pancreatic neck, the portal vein and RRHA or RCHA are separated off the pancreatic neck. In case of the RCHA, the gastroduodenal artery originating from the RCHA is divided during this dissection.

Results

The video shows a secure procedure to preserve a RCHA in laparoscopic PD by early identification and dissection of the aberrant artery via the posterior approach.

Conclusions

The posterior approach can help to prevent inadvertent RRHA or RCHA injury in laparoscopic PD.     

Genetic polymorphisms for BDNF,COMT, and APOE do not affect gait or ankle motor control in chronic stroke: A preliminary cross-sectional study

ABSTRACT

Background: Motor deficits after stroke are a primary cause of long-term disability. The extent of functional recovery may be influenced by genetic polymorphisms.

Objectives: Determine the effect of genetic polymorphisms for brain-derived neurotrophic factor (BDNF), catechol-O-methyltransferase (COMT), and apolipoprotein E (APOE) on walking speed, walking symmetry, and ankle motor control in individuals with chronic stroke.

Methods: 38 participants with chronic stroke were compared based upon genetic polymorphisms for BDNF (presence [MET group] or absence [VAL group] of a Met allele), COMT (presence [MET group] or absence [VAL group] of a Met allele), and APOE (presence [ε4+ group] of absence [ε4- group] of ε4 allele). Comfortable and maximal walking speed were measured with the 10-m walk test. Gait spatiotemporal symmetry was measured with the GAITRite electronic mat; symmetry ratios were calculated for step length, step time, swing time, and stance time. Ankle motor control was measured as the accuracy of performing an ankle tracking task.

Results: No significant differences were detected (p ≥ 0.11) between the BDNF, COMT, or APOE groups for any variables.

Conclusions: In these preliminary findings, genetic polymorphisms for BDNF, COMT, and APOE do not appear to affect walking speed, walking symmetry, or ankle motor performance in chronic stroke.     

Simvastatin improves cerebrovascular function and counters soluble amyloid-beta, inflammation and oxidative stress in aged APP mice

Cerebrovascular dysfunctions appear to contribute to Alzheimer's disease (AD) pathogenesis and the associated cognitive decline. Recently, it has been suggested that statins could be beneficial to AD patients independently from their cholesterol-lowering effects. Using 10 month-old amyloid precursor protein transgenic mice (APP mice), we sought to reverse cerebrovascular, neuronal and memory impairments with simvastatin (20 mg/kg/day, 8 weeks). Simvastatin improved reactivity of cerebral arteries, rescued the blood flow response to neuronal activation, attenuated oxidative stress and inflammation, and reduced cortical soluble amyloid-beta (Aβ) levels and the number of Aβ plaque-related dystrophic neurites. However, at such an advanced stage of the pathology, it failed to reduce Aβ plaque load and normalize cholinergic and memory deficits. These findings demonstrate that low-dose simvastatin treatment in aged APP mice largely salvages cerebrovascular function and has benefits on several AD landmarks, which could explain some of the positive effects of statins reported in AD patients.