Uncontrolled blood pressure and therapeutic inertia in treated hypertensive patients: A retrospective cohort study using a UK general practice database

Uncontrolled blood pressure (BP) and therapeutic inertia pose significant challenges in effectively managing hypertension. This study objective was to quantify levels of uncontrolled BP and therapeutic inertia among patients treated for hypertension in primary care. This retrospective cohort study used data recorded by general practitioners from the UK Clinical Practice Research Datalink database. Adults with primary hypertension who received a recorded prescription for any antihypertensive drug between January 2015 and June 2017 (index date) were included, with a follow-up of 18 months. Primary outcomes included the percentage of patients with uncontrolled BP (defined as systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg) and of apparent therapeutic inertia (defined as two consecutive uncontrolled BP records without treatment change) during follow-up. Finally, of 581 260 patients receiving antihypertensive drug(s), 37.2% (n = 216 014) had uncontrolled BP at the index date and 30.3% (n = 175 955) had no record of BP at this date. During follow-up, 59.2% had ≥1 record of uncontrolled BP, in 22% all records showed uncontrolled BP, and 12.8% had no record of BP. Among those with uncontrolled BP at the index date, 72.9% had ≥1 record of uncontrolled BP during follow-up, and in 28.3% all records showed uncontrolled BP. Therapeutic inertia was observed in 33.1% of patients overall, and in 55.7% of those with uncontrolled BP at the index date. In conclusion, BP recording was infrequent, possibly reflecting both a low frequency of measurement and potential under-recording. Uncontrolled BP and therapeutic inertia appear to be widespread in UK general practice.

Cu segregation in Au-Cu nanoparticles exposed to hydrogen atmospheric pressure: how is fcc symmetry maintained?

In a recent work [A. Nassereddine et al., Small 2021, 17, 2104571] we reported the atomic-scale structure and dynamics of sub-4 nm sized Au nanoparticles (NPs) supported on titania in H₂ at atmospheric pressure obtained by using aberration-corrected environmental transmission electron microscopy (ETEM), density functional theory (DFT) optimizations and ab initio molecular dynamic (AIMD) simulations. Our results showed unstable Au NPs losing their face-centred cubic (fcc) symmetry (from fcc to non-fcc symmetries) and revealed the drastic effect of hydrogen adsorption. In this work, we use the same approach to study the dynamics of equiatomic Au-Cu NPs in the same range of size and the results show an enhanced structural stability upon alloying by Cu. In spite of the morphology evolution from facetted to rounded shapes, the observed Au-Cu NPs are found to keep their fcc symmetry under atmospheric hydrogen pressure. AIMD simulation evidences a Cu segregation process from the sub-surface toward the upper surface layer, and a reversed segregation of Au atoms from the surface towards the sub-surface sites. The analysis of the chemical ordering in the core shows a tendency to a local chemical ordering where Au-Cu hetero-atomic bindings are favoured. The segregating Cu seems to play a major role in reducing the fluxionality of Au-Cu NPs in H₂ and thus, maintaining their fcc symmetry.

Juno Plasma Wave Observations at Ganymede

The Juno Waves instrument measured plasma waves associated with Ganymede's magnetosphere during its flyby on 7 June, day 158, 2021. Three distinct regions were identified including a wake, and nightside and dayside regions in the magnetosphere distinguished by their electron densities and associated variability. The magnetosphere includes electron cyclotron harmonic emissions including a band at the upper hybrid frequency, as well as whistler-mode chorus and hiss. These waves likely interact with energetic electrons in Ganymede's magnetosphere by pitch angle scattering and/or accelerating the electrons. The wake is accentuated by low-frequency turbulence and electrostatic solitary waves. Radio emissions observed before and after the flyby likely have their source in Ganymede's magnetosphere.

Magnetosphere-Ionosphere-Thermosphere Coupling Study at Jupiter Based on Juno's First 30 Orbits and Modeling Tools

The dynamics of the Jovian magnetosphere is controlled by the interplay of the planet's fast rotation, its solar-wind interaction and its main plasma source at the Io torus, mediated by coupling processes involving its magnetosphere, ionosphere, and thermosphere. At the ionospheric level, these processes can be characterized by a set of parameters including conductances, field-aligned currents, horizontal currents, electric fields, transport of charged particles along field lines including the fluxes of electrons precipitating into the upper atmosphere which trigger auroral emissions, and the particle and Joule heating power dissipation rates into the upper atmosphere. Determination of these key parameters makes it possible to estimate the net transfer of momentum and energy between Jovian upper atmosphere and equatorial magnetosphere. A method based on a combined use of Juno multi-instrument data and three modeling tools was developed by Wang et al. (2021, https://doi.org/10.1029/2021ja029469) and applied to an analysis of the first nine orbits to retrieve these parameters along Juno's magnetic footprint. We extend this method to the first 30 Juno science orbits and to both hemispheres. Our results reveal a large variability of these parameters from orbit to orbit and between the two hemispheres. They also show dominant trends. Southern current systems are consistent with the generation of a region of sub-corotating ionospheric plasma flows, while both super-corotating and sub-corotating plasma flows are found in the north. These results are discussed in light of the previous space and ground-based observations and currently available models of plasma convection and current systems, and their implications are assessed.

Preclinical Evaluation of White Led-Activated Non-porphyrinic Photosensitizer OR141 in 3D Tumor Spheroids and Mouse Skin Lesions

Photodynamic therapy (PDT) is used to treat malignancies and precancerous lesions. Near-infrared light delivered by lasers was thought for a while to be the most appropriate option to activate photosensitizers, mostly porphyrins, in the depth of the diseased tissues. More recently, however, several advantages including low cost and reduced adverse effects led to consider light emitting diodes (LED) and even daylight as an alternative to use PDT to treat accessible lesions. In this study we examined the capacity of OR141, a recently identified non-porphyrin photosensitizer (PS), to exert significant cytotoxic effects in various models of skin lesions and tumors upon white light activation. Using different cancer cell lines, we first identified LED lamp as a particularly suited source of light to maximize anti-proliferative effects of OR141. We then documented that OR141 diffusion and light penetration into tumor spheroids both reached thresholds compatible with the induction of cell death deep inside these 3D culture models. We further identified Arlasove as a clinically suitable solvent for OR141 that we documented by using Franz cells to support significant absorption of the PS through human skin. Finally, using topical but also systemic administration, we validated growth inhibitory effects of LED-activated OR141 in mouse skin tumor xenograft and precancerous lesions models. Altogether these results open clinical perspectives for the use of OR141 as an attractive PS to treat superficial skin malignant and non-malignant lesions using affordable LED lamp for photoactivation.

Promoting the clearance of neurotoxic proteins in neurodegenerative disorders of ageing

Neurodegenerative disorders of ageing (NDAs) such as Alzheimer disease, Parkinson disease, frontotemporal dementia, Huntington disease and amyotrophic lateral sclerosis represent a major socio-economic challenge in view of their high prevalence yet poor treatment. They are often called 'proteinopathies' owing to the presence of misfolded and aggregated proteins that lose their physiological roles and acquire neurotoxic properties. One reason underlying the accumulation and spread of oligomeric forms of neurotoxic proteins is insufficient clearance by the autophagic-lysosomal network. Several other clearance pathways are also compromised in NDAs: chaperone-mediated autophagy, the ubiquitin-proteasome system, extracellular clearance by proteases and extrusion into the circulation via the blood-brain barrier and glymphatic system. This article focuses on emerging mechanisms for promoting the clearance of neurotoxic proteins, a strategy that may curtail the onset and slow the progression of NDAs.

Synergistic enhancing-memory effect of donepezil and S 47445, an AMPA positive allosteric modulator, in middle-aged and aged mice

Positive allosteric modulators of AMPA receptors (AMPA-PAMs) are described to facilitate cognitive processes in different memory-based models. Among them, S 47445 is a novel potent and selective AMPA-PAM. In order to assess its efficacy after repeated administration, S 47445 effect was evaluated in two aging-induced memory dysfunction tasks in old mice, one short-term working memory model evaluated in a radial maze task and one assessing contextual memory performance. S 47445 was shown to improve cognition in both models sensitive to aging. In fact, administration of S 47445 at 0.3 mg/kg (s.c.) reversed the age-induced deficits of the working memory model whatever the retention interval. Moreover, in the contextual task, S 47445 also reversed the age-induced deficit at all tested doses (from 0.03 to 0.3 mg/kg, p.o.). Since donepezil, an acetylcholinesterase inhibitor, induces only moderate symptomatic effects on memory in Alzheimer's disease patients, an alternative strategy for treatment of cognitive symptoms could be to act simultaneously on both glutamatergic AMPA receptors and cholinergic pathways by combining pharmacological treatments. The present study further examined such effects by assessing combinations of S 47445 and donepezil given orally during 9 days in aged C57/Bl6J mice using contextual memory task (CSD) and the working memory model of serial alternation task (AT). Interestingly, a significant synergistic memory-enhancing effect was observed with the combination of donepezil at 0.1 mg/kg with S 47445 at 0.1 mg/kg p.o. in the CSD or with S 47445 at 0.1 and 0.3 mg/kg in AT in comparison to compounds given alone and without any pharmacokinetic interaction.

Tau accumulation in the retina promotes early neuronal dysfunction and precedes brain pathology in a mouse model of Alzheimer's disease

Background

Tau is an axon-enriched protein that binds to and stabilizes microtubules, and hence plays a crucial role in neuronal function. In Alzheimer’s disease (AD), pathological tau accumulation correlates with cognitive decline. Substantial visual deficits are found in individuals affected by AD including a preferential loss of retinal ganglion cells (RGCs), the neurons that convey visual information from the retina to the brain. At present, however, the mechanisms that underlie vision changes in these patients are poorly understood. Here, we asked whether tau plays a role in early retinal pathology and neuronal dysfunction in AD.

Methods

Alterations in tau protein and gene expression, phosphorylation, and localization were investigated by western blots, qPCR, and immunohistochemistry in the retina and visual pathways of triple transgenic mice (3xTg) harboring mutations in the genes encoding presenilin 1 (PS1M146 V), amyloid precursor protein (APPSwe), and tau (MAPTP301L). Anterograde axonal transport was assessed by intraocular injection of the cholera toxin beta subunit followed by quantification of tracer accumulation in the contralateral superior colliculus. RGC survival was analyzed on whole-mounted retinas using cell-specific markers. Reduction of tau expression was achieved following intravitreal injection of targeted siRNA.

Results

Our data demonstrate an age-related increase in endogenous retinal tau characterized by epitope-specific hypo- and hyper-phosphorylation in 3xTg mice. Retinal tau accumulation was observed as early as three months of age, prior to the reported onset of behavioral deficits, and preceded tau aggregation in the brain. Intriguingly, tau build up occurred in RGC soma and dendrites, while tau in RGC axons in the optic nerve was depleted. Tau phosphorylation changes and missorting correlated with substantial defects in anterograde axonal transport that preceded RGC death. Importantly, targeted siRNA-mediated knockdown of endogenous tau improved anterograde transport along RGC axons.

Conclusions

Our study reveals profound tau pathology in the visual system leading to early retinal neuron damage in a mouse model of AD. Importantly, we show that tau accumulation promotes anterograde axonal transport impairment in vivo, and identify this response as an early feature of neuronal dysfunction that precedes cell death in the AD retina. These findings provide the first proof-of-concept that a global strategy to reduce tau accumulation is beneficial to improve axonal transport and mitigate functional deficits in AD and tauopathies.

Lipophilicity of PCBs and fatty acids determines their mobilisation from blubber of weaned northern elephant seal pups

Polychlorinated biphenyls (PCBs) exhibit lipophilic properties that lead to their bioaccumulation in adipose tissue. Following PCB exposition, northern elephant seals (Mirounga angustirostris) concentrate high amounts of these pollutants in their large adipose tissue stores. During lipolytic periods such as the post-weaning fast, fatty acids (FAs), which form triglycerides, and PCBs are both mobilised from adipose tissue. Our results showed that the degree of lipophilicity of FAs and PCBs impacted their release: the more lipophilic FAs and PCBs tended to be more conserved in blubber over the fast than the less lipophilic ones. This led to an enrichment of more lipophilic compounds within adipocytes with the progression of the fast. Life history patterns that include fasting may thus influence the profile of blubber lipids and contaminants.

Hippocampal Injections of Oligomeric Amyloid β-peptide (1-42) Induce Selective Working Memory Deficits and Long-lasting Alterations of ERK Signaling Pathway

Increasing evidence suggests that abnormal brain accumulation of soluble rather than aggregated amyloid-β1-42 oligomers (Aβo(1-42)) plays a causal role in Alzheimer's disease (AD). However, as yet, animal's models of AD based on oligomeric amyloid-β1-42 injections in the brain have not investigated their long-lasting impacts on molecular and cognitive functions. In addition, the injections have been most often performed in ventricles, but not in the hippocampus, in spite of the fact that the hippocampus is importantly involved in memory processes and is strongly and precociously affected during the early stages of AD. Thus, in the present study, we investigated the long-lasting impacts of intra-hippocampal injections of oligomeric forms of Aβo(1-42) on working and spatial memory and on the related activation of ERK1/2. Indeed, the extracellular signal-regulated kinase (ERK) which is involved in memory function had been found to be activated by amyloid peptides. We found that repeated bilateral injections (1injection/day over 4 successive days) of oligomeric forms of Aβo(1-42) into the dorsal hippocampus lead to long-lasting impairments in two working memory tasks, these deficits being observed 7 days after the last injection, while spatial memory remained unaffected. Moreover, the working memory deficits were correlated with sustained impairments of ERK1/2 activation in the medial prefrontal cortex (mPFC) and the septum, two brain areas tightly connected with the hippocampus and involved in working memory. Thus, our study is first to evidence that sub-chronic injections of oligomeric forms of Aβo(1-42) into the dorsal hippocampus produces the main sign of cognitive impairments corresponding to the early stages of AD, via long-lasting alterations of an ERK/MAPK pathway in an interconnected brain networks.

[Not Available]

PURPOSE OF THE STUDY

To evaluate the efficacy of fractionated stereotactic reirradiation with CyberKnife (CK) performed in 6 patients with high grade gliomas treated in Luxembourg with local recurrence (LR).

PATIENTS AND METHODS

Between 04.2014 and 06.2016, 6 patients with multiform grade IV gliomas LR were reirradiated with CK (protocol CNER re-RT CFB 1), as reirradiation. The mean time between primary radiotherapy and local recurrence (LR) is 14.1 months [4 - 38]. CK is performed with a dose of 36 Gy in 6 fractions (5 cases) and 30 Gy in 3 fractions (1 case) Results : LR after CK (progression free survival) is 3.4 months [2 - 7] (5 cases assessment). Mean survival after CK is 12 months [3 - 22] (3 cases assessment). Mean survival after initial diagnosis is 37 months [17 - 58] (3 cases assessment). No toxicity is noticed (4 cases assessment). Time to first progression after primary treatment is a strong predictor for survival. Fractionated stereotactic reirradiation with CK is well tolerated and effective (survival) in patients with LR high grade gliomas. In accordance with these results, the CFB Conseil Scientifique recommends a new paradigm for MRI follow-up high grade gliomas. After first line treatment, an MRI has to be performed every 3 months, to identify LR earlier, and to offer the patients a way of salvage with CK option, in order to increase his chances of better survival.

A new ER-specific photosensitizer unravels (1)O2-driven protein oxidation and inhibition of deubiquitinases as a generic mechanism for cancer PDT

Photosensitizers (PS) are ideally devoid of any activity in the absence of photoactivation, and rely on molecular oxygen for the formation of singlet oxygen ((1)O2) to produce cellular damage. Off-targets and tumor hypoxia therefore represent obstacles for the use of PS for cancer photodynamic therapy. Herein, we describe the characterization of OR141, a benzophenazine compound identified through a phenotypic screening for its capacity to be strictly activated by light and to kill a large variety of tumor cells under both normoxia and hypoxia. This new class of PS unraveled an unsuspected common mechanism of action for PS that involves the combined inhibition of the mammalian target of rapamycin (mTOR) signaling pathway and proteasomal deubiquitinases (DUBs) USP14 and UCH37. Oxidation of mTOR and other endoplasmic reticulum (ER)-associated proteins drives the early formation of high molecular weight (MW) complexes of multimeric proteins, the concomitant blockade of DUBs preventing their degradation and precipitating cell death. Furthermore, we validated the antitumor effects of OR141 in vivo and documented its highly selective accumulation in the ER, further increasing the ER stress resulting from (1)O2 generation upon light activation.

Oleate Abrogates Palmitate-Induced Lipotoxicity and Proinflammatory Response in Human Bone Marrow-Derived Mesenchymal Stem Cells and Osteoblastic Cells

Osteoporosis is a metabolic bone disease associated with unequilibrated bone remodeling resulting from decreased bone formation and/or increased bone resorption, leading to progressive bone loss. In osteoporotic patients, low bone mass is associated with an increase of bone marrow fat resulting from accumulation of adipocytes within the bone marrow. Marrow adipocytes are active secretory cells, releasing cytokines, adipokines and free fatty acids (FA) that influence the bone marrow microenvironment and alter the biology of neighboring cells. Therefore, we examined the effect of palmitate (Palm) and oleate (Ole), 2 highly prevalent FA in human organism and diet, on the function and survival of human mesenchymal stem cells (MSC) and MSC-derived osteoblastic cells. The saturated FA Palm exerted a cytotoxic action via initiation of endoplasmic reticulum stress and activation of the nuclear factor κB (NF-κB) and ERK pathways. In addition, Palm induced a proinflammatory response, as determined by the up-regulation of Toll-like receptor 4 expression as well as the increase of IL-6 and IL-8 expression and secretion. Moreover, we showed that MSC-derived osteoblastic cells were more sensitive to lipotoxicity than undifferentiated MSC. The monounsaturated FA Ole fully neutralized Palm-induced lipotoxicity by impairing activation of the pathways triggered by the saturated FA. Moreover, Ole promoted Palm detoxification by fostering its esterification into triglycerides and storage in lipid droplets. Altogether, our data showed that physiological concentrations of Palm and Ole differently modulated cell death and function in bone cells. We therefore propose that FA could influence skeletal health.

Deficits of psychomotor and mnesic functions across aging in mouse lemur primates

Owing to a similar cerebral neuro-anatomy, non-human primates are viewed as the most valid models for understanding cognitive deficits. This study evaluated psychomotor and mnesic functions of 41 young to old mouse lemurs (Microcebus murinus). Psychomotor capacities and anxiety-related behaviors decreased abruptly from middle to late adulthood. However, mnesic functions were not affected in the same way with increasing age. While results of the spontaneous alternation task point to a progressive and widespread age-related decline of spatial working memory, both spatial reference and novel object recognition (NOR) memory tasks did not reveal any tendency due to large inter-individual variability in the middle-aged and old animals. Indeed, some of the aged animals performed as well as younger ones, whereas some others had bad performances in the Barnes maze and in the object recognition test. Hierarchical cluster analysis revealed that declarative-like memory was strongly impaired only in 7 out of 25 middle-aged/old animals. These results suggest that this analysis allows to distinguish elder populations of good and bad performers in this non-human primate model and to closely compare this to human aging.

Bioaccumulation of hydroxylated polychlorinated biphenyls and pentachlorophenol in the serum of northern elephant seal pups (Mirounga angustirostris)

Northern elephant seals (NES) (Mirounga angustirostris) from the Año Nuevo State Reserve (CA, USA) were sampled at 1-, 4-, 7- and 10-week post-weaning. Concentrations of hydroxylated polychlorinated biphenyls (HO-PCBs) and their parent PCBs were measured in the serum of each individual. The ΣHO-PCB concentrations in the serum increased significantly between early and late fast (from 282 ± 20 to 529 ± 31 pg/mL). This increase might result from a mobilisation of HO-PCBs transferred from the mother during gestation and/or lactation and stored in the pup's liver. Food deprivation has been shown to exacerbate biotransformation capacities in mammals, birds and fish. The HO-penta-CBs was the predominant homologue group, followed by HO-hexa-CBs and HO-hepta-CBs. No preferential pathway for the metabolism of HO-PCBs (HO-direct insertion or NIH-shift of a chlorine atom) could be evidenced. The concentrations of pentachlorophenol (PCP) in the serum of weaned NES increased from 103 ± 7 pg/mL at early fast to 246 ± 41 pg/mL at late fast, which is within the range of PCP concentrations usually encountered in marine mammals.

The use of theranostic gadolinium-based nanoprobes to improve radiotherapy efficacy

A new efficient type of gadolinium-based theranostic agent (AGuIX®) has recently been developed for MRI-guided radiotherapy (RT). These new particles consist of a polysiloxane network surrounded by a number of gadolinium chelates, usually 10. Owing to their small size (<5 nm), AGuIX typically exhibit biodistributions that are almost ideal for diagnostic and therapeutic purposes. For example, although a significant proportion of these particles accumulate in tumours, the remainder is rapidly eliminated by the renal route. In addition, in the absence of irradiation, the nanoparticles are well tolerated even at very high dose (10 times more than the dose used for mouse treatment). AGuIX particles have been proven to act as efficient radiosensitizers in a large variety of experimental in vitro scenarios, including different radioresistant cell lines, irradiation energies and radiation sources (sensitizing enhancement ratio ranging from 1.1 to 2.5). Pre-clinical studies have also demonstrated the impact of these particles on different heterotopic and orthotopic tumours, with both intratumoural or intravenous injection routes. A significant therapeutical effect has been observed in all contexts. Furthermore, MRI monitoring was proven to efficiently aid in determining a RT protocol and assessing tumour evolution following treatment. The usual theoretical models, based on energy attenuation and macroscopic dose enhancement, cannot account for all the results that have been obtained. Only theoretical models, which take into account the Auger electron cascades that occur between the different atoms constituting the particle and the related high radical concentrations in the vicinity of the particle, provide an explanation for the complex cell damage and death observed.

Mobilisation of lipophilic pollutants from blubber in northern elephant seal pups (Mirounga angustirostris) during the post-weaning fast

Northern elephant seals (NES) (Mirounga angustirostris) from the Año Nuevo State Reserve (CA, USA) were longitudinally sampled during the post-weaning fast in order to study the mobilisation and redistribution of various classes of persistent organic pollutants (POPs), such as polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlorobenzene (HCB) between blubber and blood. Inner and outer blubber layers were analysed separately. Organohalogenated compounds were detected in all blubber samples in the decreasing order of their concentrations: p,p'-DDE > PCBs ⪢ HCB > PBDEs. The concentrations of all studied compounds were homogeneously distributed in the blubber layer at early fast, since the concentrations of POPs were statistically not different in the inner and outer layers. With the progression of the fast, the concentrations of PBDEs, PCBs and p,p'-DDE increased more sharply in inner blubber than in outer blubber. As a result, their levels became significantly higher in inner blubber as compared to outer blubber at late fast. The rise of pollutant concentrations in blubber might result from a less efficient mobilisation than triglycerides and/or a reuptake by adipocytes of some of the pollutants released into the circulation. The mobilisation of pollutants from blubber was higher at late fast. An increase of pollutant concentrations was observed in serum between early and late fast. Lower halogenated congeners (i.e. tetra-CBs) were present in higher proportions in serum, whereas the higher halogenated congeners (i.e. hepta-CBs) were mainly found in the inner and outer blubber layers. The transfer ratios of both PBDEs and PCBs from inner blubber to serum decreased with the number of chlorine and bromine atoms. In addition, the distribution of both types of compounds between serum and blubber was strongly influenced by their lipophilic character (logKow values), with more lipophilic compounds being less efficiently released from blubber to serum.

Efficient in vitro adipocyte model of long-term lipolysis: a tool to study the behavior of lipophilic compounds

The triglycerides (TGs) stored in the white adipose tissue are mobilized during periods of negative energy balance. To date, there is no in vitro model of adipocytes imitating a long period of negative energy balance in which triglycerides are highly mobilized. Such model would allow studying the mobilization of TGs and lipophilic compounds trapped within the adipose tissue (e.g., pollutants and vitamins). The present study aims at developing a performing long-term in vitro lipolysis in adipocytes, resulting in a significant decrease of TG stores. Lipolysis was induced on differentiated rat adipocytes by a lipolytic medium with or without isoproterenol for 12 h. The condition with isoproterenol was duplicated, once with medium renewal every 3 h and once without medium renewal. Adding isoproterenol efficiently triggered lipolysis in a short time (3 h). However, a single stimulation by isoproterenol, without medium renewal, was not sufficient to reduce the TG content during a longer term (12 h). A reesterification of fatty acids occurred after a few hours of lipolysis, resulting in a novel increase of cellular lipids. Regular medium renewal combined with repeated isoproterenol stimulations led to almost emptied cells after 12 h. However, medium renewal without isoproterenol stimulation for 12 h was as efficient in terms of lipid mobilization. Our study demonstrates that, over a short-term period, isoproterenol is required to exert a significant lipolytic effect on adipocytes. During a long-term period, the presence of isoproterenol is no longer essential. Instead, medium renewal becomes the main factor involved in cell emptying. The efficiency of this protocol was demonstrated by visual tracking of the cells and by monitoring the dynamics of release of a lipophilic compound, PCB-153, from adipocytes during lipolysis.

Working memory deficits and related disinhibition of the cAMP/PKA/CREB are alleviated by prefrontal α4β2*-nAChRs stimulation in aged mice

The present study investigates in aged mice the working memory (WM) enhancing potential of the selective α4β2* nicotinic receptor agonist S 38232 as compared with the cholinesterase inhibitor donepezil, and their effect on cAMP response element binding protein (CREB) phosphorylation (pCREB) as a marker of neuronal activity. We first showed that aged mice exhibit a WM deficit and an increase of pCREB in the prelimbic cortex (PL) as compared with young mice, whereas no modification appears in the CA1. Further, we showed that systemic administration of S 38232 restored WM in aged mice and alleviated PL CREB overphosphorylation. Donepezil alleviated age-related memory deficits, however, by increasing pCREB in the CA1, while pCREB in PL remained unaffected. Finally, whereas neuronal inhibition by lidocaine infusion in the PL appeared deleterious in young mice, the infusion of Rp-cAMPS (a compound known to inhibit CREB phosphorylation) or S 38232 rescued WM in aged animals. Thus, by targeting the α4β2*-nicotinic receptor of the PL, S 38232 alleviates PL CREB overphosphorylation and restores WM in aged mice, which opens new pharmacologic perspectives of therapeutic strategy.

[Long-term fever after gastric banding]

We report a 65-year-old male, suffering from aspiration pneumonia after gastric banding revealed by intermittent fever inducing a delayed diagnosis. Several early and later pulmonary complications following laparoscopic gastric banding have been reported. Removal or deflation of the band should be considered in unexplained persistent fever to avoid more severe complications such as respiratory distress.

Effects of positive modulators of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors in a benzodiazepine-induced deficit of spatial discrimination in mice

Imbalance between GABAergic and glutamatergic neurotransmission has been recently hypothesized to trigger memory decline related either to ageing or to Alzheimer's disease (AD). Thereby, benzodiazepine-induced anterograde amnesia has been construed as a model of hippocampal-related cognitive dysfunctions. Since spatial memory is altered both by ageing and by benzodiazepines such as alprazolam, we investigated the pharmacological sensitivity of alprazolam-induced deficit in a delayed spatial discrimination (SD) task, notably with positive allosteric modulators of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors. We showed that alprazolam (0.1 mg/kg intraperitoneally) induced memory impairments as compared with vehicle-treated mice. The oral administration of modulators of AMPA receptors (IDRA-21: 10 mg/kg; S18986: 3 and 10 mg/kg) reversed the alprazolam-induced deficits. This study is first to show evidence that reference treatments of AD, such as memantine (a NMDA receptor antagonist) at 3 mg/kg per os (po) and donepezil (an acetylcholinesterase inhibitor) at 1 mg/kg po, also reversed the alprazolam-induced amnesia. Given such results, the SD task emerges as a valuable novel task to screen pro-cognitive compounds. Thus, we highlight the efficacy of modulators of AMPA-type glutamate receptors to counteract alprazolam-induced spatial deficits. These results could be viewed alongside the imbalance between excitation and inhibition observed during normal and pathological ageing.

Accumulation of polychlorinated biphenyls in adipocytes: selective targeting to lipid droplets and role of caveolin-1

Background

Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that preferentially accumulate in lipid-rich tissues of contaminated organisms. Although the adipose tissue constitutes a major intern reservoir of PCBs and recent epidemiological studies associate PCBs to the development of obesity and its related disorders, little is known about the mechanisms involved in their uptake by the adipose tissue and their intracellular localization in fat cells.

Methodology/Principal Findings

We have examined the intracellular distribution of PCBs in mouse cultured adipocytes and tested the potential involvement of caveolin-1, an abundant adipocyte membrane protein, in the uptake of these compounds by fat cells. We show that 2,4,4′-trichlorobiphenyl (PCB-28), 2,3′,4,4′,5-pentachlorobiphenyl (PCB-118) and 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB-153) congeners rapidly and extensively accumulate in 3T3-L1 or mouse embryonic fibroblast (MEF) derived cultured adipocytes. The dynamics of accumulation differed between the 3 congeners tested. By subcellular fractionation of primary adipocytes, we demonstrate that these pollutants were almost exclusively recovered within the lipid droplet fraction and practically not associated to cell membranes. The absence of caveolin-1 expression in primary adipocytes from cav-1 deficient mice did not modify lipid droplet selective targeting of PCBs. In cav-1 KO MEF differentiated adipocytes, PCB accumulation was decreased, which correlated with reduced cell triglyceride content. Conversely, adenoviral mediated cav-1 overexpressing in 3T3-L1 cells, which had no impact on total cell lipid content, did not change PCB accumulation.

Conclusion/Significance

Our data indicate that caveolin-1 per se is not required for selective PCB accumulation, but rather point out a primary dependence on adipocyte triglyceride content. If the crucial role of lipid droplets in energy homeostasis is considered, the almost exclusive accumulation of PCBs in these organelles warrants future attention as the impairment of their function could be linked to the worldwide obesity epidemic.

S 18986 reverses spatial working memory impairments in aged mice: comparison with memantine

RATIONALE

Normal or pathological ageing is characterized by working-memory dysfunction paired with a marked reduction in several neurotransmitters activity. The development of therapeutic strategy centered on the glutamatergic system known to bear a critical role in cognitive functions, is therefore of major importance in the treatment of mild forms of AD or age-related memory dysfunctions.

OBJECTIVES

In Experiment 1, we investigated the effects of ageing on spatial working memory measured by sequential alternation (SA). Thus, the decay of alternation rates over a series of trials separated by varying intertrial temporal intervals (ITI, from 5 sec to 180 sec) was studied in mice of different age groups. In Experiment 2, we investigated the memory-enhancing potential of S 18986--a modulator of AMPA receptors--on age-related SA impairments, in comparison with memantine--an antagonist of NMDA receptors--.

RESULTS

In Experiment 1, aged mice responded at chance with shorter ITI's and exhibited greater levels of interference in the SA task as compared to young adult mice. In Experiment 2, (1) S 18986 at 0.03 and 0.1 mg/kg reversed the memory deficit in aged mice but did not modify performance in young adult mice; (2) memantine at 10 mg/kg also increased SA rates in aged mice but did not improve performance in young adult mice.

CONCLUSION

The SA task is a useful tool to reveal age-induced time-dependent working memory impairments. As compared to memantine, S 18986--a compound targeting AMPA receptors--contributes a valuable therapy in the treatment of age-related cognitive dysfunctions or mild forms of AD.

Stereotactic radiotherapy of hepatocellular carcinoma: preliminary results

Stereotactic radiotherapy (SRT) offers a treatment option for hepatocellular carcinoma (HCC) patients that are not eligible for surgery, embolization, chemotherapy, or radiofrequency ablation. We have evaluated the feasibility, tolerance and toxicity of SRT for 25 HCC patients who were not eligible for these other modalities. The patients (6 women and 19 men) were treated with CyberKnife stereotactic radiotherapy using respiratory motion tracking. All patients had liver cirrhosis with an Eastern Cooperative Oncology Group (ECOG) performance score of less than 2 and pre-treatment Child scores ranging from A5 to B9. A total dose of 45 Gy in three fractions of 15 Gy each was prescribed to the 80% isodose line (95% of the PTV received 45 Gy) and delivered to the target volume over 10 to 12 days. Overall the treatment was well tolerated with two Grade 3 acute toxicities and no acute Grade 4 toxicities. Late toxicity was minimal with all observed late toxicities occurring within the first six months of follow-up. Three hepatic recurrences at a distance from the target and one metastasis were observed. The actuarial 1- and 2-year local control rate was 95% (95% CI: 69-95%). At a median overall follow-up of 12,7 months (range, 1-24 months), six of the twenty-five (24%) patients have died. Overall actuarial survival at 1- and 2-years was 79% (95% CI: 52-92%) and 52% (95% CI: 19-78%), respectively. Our results suggest promising therapeutic efficacy and good clinical tolerance to CyberKnife SRT treatment for HCC patients not eligible for other treatment modalities.

Multi-luminescent hybrid gadolinium oxide nanoparticles as potential cell labeling

This manuscript analyses the use of newly developed hybrid gadolinium oxide nanoparticles as cell-labeling tracers. The nanoparticles are core-shell particles composed of a core of gadolinium oxide of [2-4] nm and a protecting shell of polysiloxane [1-3 nm] where different organic dyes (fluoresceine isothiocyanate (FITC) or rhodamine B isothiocyanate (RBITC)) are embedded. They are functionalized with poly(ethylene glycol)bis(carboxymethyl) to ensure their colloidal stability in biological buffers. These particles are potential multi-labeling tracers (magnetic and optical). In this paper, we show by optical imaging that they can be efficiently internalized in cells without cell alteration. The in-vitro uptake of the nanoparticles was followed in two cell lines (human fibroblasts and a human adenocarnima cell lines MCF7 cells). Nanoparticles distribution within cells was analysed by confocal analysis, and gadolinium concentration within cells was quantified by mass spectrometry (ICP-MS analysis). Nanoparticles uptake is found to be fast and efficient for both cell lines, with fluorescent labeling visible after 10 min of incubation whatever the nature of the fluorophore. The fluorescent intensity is mainly found as concentrated dots in the perinuclear region of the cells and decreases with the number of days in culture, but is still easily detectable after 3 days in culture. No significant effect on cell growth was detected. Finally, we show in this study the protective effect of the polysiloxane layer: encapsulation of RBITC within the polysiloxane shell, leads to a better photostability of this low cost dye than Cy3 and even reach a level comparable to Alexa 595. With their high photostability and long-lasting contrast properties, these hybrid luminescent nanoparticles appears thus as a versatile solution to assess multiple cell fate both in in-vitro cell model as well as in-vivo.

Variability of origin for the neocentromeric sequences in analphoid supernumerary marker chromosomes of well-differentiated liposarcomas

Well-differentiated liposarcomas (WDLPS) and dedifferentiated liposarcomas are cytogenetically characterized by the presence of supernumerary ring or giant chromosomes containing amplified material from the 12q14-15 region. These chromosomes contain neocentromeres, which are able to bind the kinetochore proteins and to ensure a stable mitotic transmission although they do not show detectable alpha-satellite sequences. WDLPS is the sole solid tumor for which the presence of a neocentromere is a consistent and specific feature. By immunostaining with anti-centromere antibodies in combination with FISH analysis (immunoFISH) in four cases of WDLPS, we have shown that sequences from the region 12q14-21 region were not located at the neocentromere site. In addition, we have microdissected the neocentromeric region from a giant supernumerary chromosome in the 94T778 WDLPS cell line. By using immunoFISH and positional cloning we have shown that the neocentromere of this cell line originated from a region at 4p16.1, rich in AT sequences and in long interspersed nucleotide element (LINE)1, that was co-amplified with 12q14-15. We have observed that this 4p sequence was not involved in the neocentromere of the supernumerary giant chromosome present in the 93T449 WDLPS cell line derived from a metachronous recurrence of the same primary WDLPS than 94T778. Altogether, these results indicate that the neocentromeres in WDLPS originate from amplified chromosomal regions other than 12q14-15 and do not involve a specific and recurrent DNA sequence. These sequences might be activated for centromeric function by epigenetic mechanisms.

Anatomical ontologies of mosquitoes and ticks, and their web browsers in VectorBase

VectorBase, an integrated, relational database that manages genomic and other genetic/biological data pertaining to arthropod vectors of disease, has recently embarked on the construction of ontologies and controlled vocabularies (CVs). It aims, thus, at providing all necessary tools for the complete annotation of vector genomes and, in particular, the annotation of functional genomic data. This task was initiated with the development of anatomical ontologies of mosquitoes and ticks, both of which were made compliant to CARO, the common anatomy reference ontology. The ontologies are complemented by the development of novel web-based browsers that can show figures for anatomical terms, something that is especially helpful for fully illustrating the controlled vocabularies of anatomy.

Additional evidence for anxiolytic- and antidepressant-like activities of saredutant (SR48968), an antagonist at the neurokinin-2 receptor in various rodent-models

Central tachykinins have been shown to play a role in the modulation of stress-related behaviours. Saredutant, a tachykinin NK2 receptor antagonist, displayed mixed anxiolytic- and antidepressant-like activities in rodents. The present study aimed at further characterizing its psychotropic properties. Saredutant was tested in the rat social interaction test to further confirm its anxiolytic-like activity, and in a variety of behavioural models sensitive to antidepressant drugs. In the rat social interaction test, saredutant (20 mg/kg, i.p.) significantly increased the time spent in interaction, as did the prototypical anxiolytic agents, diazepam (1 mg/kg, i.p.) and buspirone (1 mg/kg, s.c.), but not the antidepressant, fluoxetine. In a differential reinforcement of low rate-72s task, saredutant (3 mg/kg, i.p.) displayed an antidepressant-like activity by increasing reinforced response rate and percentage of responses emitted in the inter-response time bin [49-96 s]. In bulbectomized rats, saredutant (20 mg/kg, i.p.) restored the deficit of acquisition of passive avoidance. In rat pups separated from their mother, saredutant (3-10 mg/kg, s.c.) reduced ultrasonic distress calls. Finally, in the chronic mild stress paradigm in mice, a 29-day treatment regimen with saredutant (10 mg/kg, i.p.) attenuated stress-induced physical degradation. Importantly, in the depression models, the effects of saredutant were comparable to those obtained under similar experimental conditions by reference antidepressants such as fluoxetine or imipramine. Together, these results suggest further that the NK2 receptor may represent an attractive target for the treatment of both depressive and anxiety disorders.