Isotopic Control of the Boron-Vacancy Spin Defect in Hexagonal Boron Nitride

We report on electron spin resonance (ESR) spectroscopy of boron-vacancy (V_{B}^{-}) centers hosted in isotopically engineered hexagonal boron nitride (hBN) crystals. We first show that isotopic purification of hBN with ^{15}N yields a simplified and well-resolved hyperfine structure of V_{B}^{-} centers, while purification with ^{10}B leads to narrower ESR linewidths. These results establish isotopically purified h^{10}B^{15}N crystals as the optimal host material for future use of V_{B}^{-} spin defects in quantum technologies. Capitalizing on these findings, we then demonstrate optically induced polarization of ^{15}N nuclei in h^{10}B^{15}N, whose mechanism relies on electron-nuclear spin mixing in the V_{B}^{-} ground state. This work opens up new prospects for future developments of spin-based quantum sensors and simulators on a two-dimensional material platform.

Optically Active Spin Defects in Few-Layer Thick Hexagonal Boron Nitride

Optically active spin defects in hexagonal boron nitride (hBN) are promising quantum systems for the design of two-dimensional quantum sensing units offering optimal proximity to the sample being probed. In this Letter, we first demonstrate that the electron spin resonance frequencies of boron vacancy centers (V_{B}^{-}) can be detected optically in the limit of few-atomic-layer thick hBN flakes despite the nanoscale proximity of the crystal surface that often leads to a degradation of the stability of solid-state spin defects. We then analyze the variations of the electronic spin properties of V_{B}^{-} centers with the hBN thickness with a focus on (i) the zero-field splitting parameters, (ii) the optically induced spin polarization rate and (iii) the longitudinal spin relaxation time. This Letter provides important insights into the properties of V_{B}^{-} centers embedded in ultrathin hBN flakes, which are valuable for future developments of foil-based quantum sensing technologies.

Adipose tissue angiogenesis genes are down-regulated by grape polyphenols supplementation during a human overfeeding trial

The adaptive response to overfeeding is associated with profound modifications of gene expression in adipose tissue to support lipid storage and weight gain. The objective of this study was to assess in healthy lean men whether a supplementation with polyphenols could interact with these molecular adaptations. Abdominal subcutaneous adipose tissue biopsies were sampled from 42 subjects participating to an overfeeding protocol providing an excess of 50% of their total energy expenditure for 31 days, and who were supplemented with 2 g/day of grape polyphenols or a placebo. Gene expression profiling was performed by RNA sequencing. Overfeeding led to a modification of the expression of 163 and 352 genes in the placebo and polyphenol groups, respectively. The GO functions of these genes were mostly involved in lipid metabolism, followed by genes involved in adipose tissue remodeling and expansion. In response to overfeeding, 812 genes were differentially regulated between groups. Among them, a set of 41 genes were related to angiogenesis and were downregulated in the polyphenol group. Immunohistochemistry targeting PECAM1, as endothelial cell marker, confirmed reduced angiogenesis in this group. Finally, quercetin and isorhamnetin, two polyphenol species enriched in the plasma of the volunteers submitted to the polyphenols, were found to inhibit human umbilical vein endothelial cells migration in vitro. Polyphenol supplementation do not prevent the regulation of genes related to lipid metabolism in human adipose tissue during overfeeding, but impact the angiogenesis pathways. This may potentially contribute to a protection against adipose tissue expansion during dynamic phase of weight gain.

Decoherence of V[Formula: see text] spin defects in monoisotopic hexagonal boron nitride

Spin defects in hexagonal boron nitride (hBN) are promising quantum systems for the design of flexible two-dimensional quantum sensing platforms. Here we rely on hBN crystals isotopically enriched with either 10B or 11B to investigate the isotope-dependent properties of a spin defect featuring a broadband photoluminescence signal in the near infrared. By analyzing the hyperfine structure of the spin defect while changing the boron isotope, we first confirm that it corresponds to the negatively charged boron-vacancy center ([Formula: see text]). We then show that its spin coherence properties are slightly improved in 10B-enriched samples. This is supported by numerical simulations employing cluster correlation expansion methods, which reveal the importance of the hyperfine Fermi contact term for calculating the coherence time of point defects in hBN. Using cross-relaxation spectroscopy, we finally identify dark electron spin impurities as an additional source of decoherence. This work provides new insights into the properties of [Formula: see text] spin defects, which are valuable for the future development of hBN-based quantum sensing foils.

Treatment patterns in patients with Familial hypercholesterolemia: evidence from real-world studies in Germany and the UK

Background

Familial hypercholesterolemia (FH) includes a spectrum of disease as per the number and effect of mutations in specific proteins involved in low-density lipoprotein cholesterol (LDL-C) metabolism, together with other genetic factors. Elevated LDL-C levels have been strongly associated with risk of cardiovascular and coronary heart disease, with up to 10-fold risk in patients (pts) with FH than without FH. The aim of lipid-lowering treatments (LLTs) is to reduce the LDL-C levels, although there is limited research describing treatment patterns and LDL-C outcomes in FH pts in routine care.

Purpose

To characterize the treatment patterns and LDL-C outcomes of FH pts in the real-world setting in Germany (GER) and the UK.

Methods

We conducted two descriptive, non-interventional and retrospective cohort studies. Pts in GER were identified from General Physician (GP) and Cardiology practices available in electronic medical records database Disease Analyzer (January 1992-June 2020). Pts in the UK were identified from the Clinical Practice Research Datalink linked to the Hospital Episode Statistics admitted pts care and Office of National Statistics datasets. Pts were included if they had diagnosis of FH (index date [ID]) and data available within 6-month before and 3-month after the ID. The first diagnosis of FH in the identification period (GER, 1/07/2015–30/06/2019; UK, 01/01/2010–31/05/2018) was considered the ID. Persistence and adherence to the recorded LLT at ID was analyzed for pts with at least 12 months and 24 months of follow-up. Persistence was measured as the duration (in days) with allowed gap of 60 days and adherence as proportion of days covered (PDC).

Results

Analysis included 2,105 FH pts from GER and 9,846 from the UK. Data are presented as GER/UK. The mean (SD) age of pts was 60 (15)/52 (14) years, and 60%/61% were females. Hypertension (53%/27%) and depression (31%/38%) were the common comorbidities. At ID, statin monotherapy (29%/68%) was the most commonly prescribed LLT. The use of ezetimibe, fibrates and PCSK9 inhibitors was very low in both countries (Table 1). Of note, LDL-C measurements at ID (−6m/+3m) were available for 31%/73% of pts. In pts with uncontrolled LDL-C (≥55 mg/dL), 34%/64% were receiving statin monotherapy, whereas there was no use of LLT in 62%/29% of pts. During the 24 months follow-up, the mean (SD) persistence and PDC to statins monotherapy was 471 (264)/489 (289) days and 0.65 (0.36)/0.69 (0.46), respectively, with 50%/70% of pts being adherent (PDC ≥0.80).

Conclusions

In our study, in GER, the rate of LDL-C measurements was low. In both GER and UK, almost all measured patients had LDL-C ≥55mg/dL at ID. Findings indicate low prescriptions of LLTs in GP setting, particularly non-statin LLTs in both countries. The mean adherence (PDC) in GER and the UK was 65% and 69%, respectively within 24 months after ID. Improved LDL-C monitoring and new therapies with potential to lower LDL-C are warranted.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Novartis Pharma AG, Basel, Switzerland

Addendum: Gouriou et al. ANT2-Mediated ATP Import into Mitochondria Protects against Hypoxia Lethal Injury. Cells 2020, 9, 2542

The authors and the Cells Editorial Office would like to add the section “Materials and Methods”, which was missing in the original version [...]

Signaling pathway deregulation and molecular alterations across pediatric medulloblastomas

Medulloblastomas (MBs) account for 15% of brain tumors in children under the age of 15. To date, the overall 5-year survival rate for all children is only around 60%. Recent advances in cancer genomics have led to a fundamental change in medulloblastoma classification and is evolving along with the genomic discoveries, allowing to regularly reclassify this disease. The previous molecular classification defined 4 groups (WNT-activated MB, SHH-activated MB and the groups 3 and 4 characterized partially by NMYC and MYC driven MBs). This stratification moved forward recently to better define these groups and their correlation to outcome. This new stratification into 7 novel subgroups was helpful to lay foundations and complementary data on the understanding regarding molecular pathways and gene mutations underlying medulloblastoma biology. This review was aimed at answering the recent key questions on MB genomics and go further in the relevance of those genes in MB development as well as in their targeted therapies.

Photodegradation of Molecular Iodine on SiO2 Particles: Influence of Temperature and Relative Humidity

A molecular derivatization method followed by gas chromatographic separation coupled with mass spectrometric detection was used to study photodegradation of molecular I2 adsorbed on solid SiO2 particles. The heterogeneous photodegradation of I2 was studied as a function of temperature and relative humidity in synthetic air to better understand its environmental fate. Two sets of experiments were carried out. In the first set of experiments, the temperature was T = (298 ± 1) K and relative humidity was varied from ≤ 2% to 75%RH under given experimental conditions. In the second set of experiments, the relative humidity within the Pyrex bulb was 40%RH and the temperature was varied from 283 ± 1 ≤ T (K) ≤ 323 ± 1. The obtained results show a considerably enhanced atmospheric lifetime of molecular iodine adsorbed on solid media that does not depend on relative humidity of the environment. The obtained results show that the rate constant for the photolysis of molecular iodine adsorbed on model SiO2 particles depends on temperature and is reported to be J (T)=(1.24 ± 1.4)×10−2×exp[(1482±345)/T]/s over the measured temperature range. The heterogeneous atmospheric residence time () of I2 adsorbed on solid media is calculated to range from 2 to 4.1 h. The experimentally obtained heterogeneous lifetime of I2 is shown to be considerably longer than its destruction by its principal atmospheric sink, photolysis. The observed enhanced atmospheric lifetime of I2 on heterogeneous media will likely have direct consequences on the atmospheric transport of I2 that influences the toxicity or the oxidative capacity of the atmosphere.

Milk polar lipids favorably alter circulating and intestinal ceramide and sphingomyelin species in postmenopausal women

BACKGROUND

High circulating levels of ceramides (Cer) and sphingomyelins (SM) are associated with cardiometabolic diseases. The consumption of whole fat dairy products, naturally containing such polar lipids (PL), is associated with health benefits, but the impact on sphingolipidome remains unknown.

METHODS

In a 4-week randomized controlled trial, 58 postmenopausal women daily consumed milk PL-enriched cream cheese (0, 3, or 5 g of milk PL). Postprandial metabolic explorations were performed before and after supplementation. Analyses included SM and Cer species in serum, chylomicrons, and feces. The ileal contents of 4 ileostomy patients were also explored after acute milk PL intake.

RESULTS

Milk PL decreased serum atherogenic C24:1 Cer, C16:1 SM, and C18:1 SM species (P_group < 0.05). Changes in serum C16+18 SM species were positively correlated with the reduction of cholesterol (r = 0.706), LDL-C (r = 0.666), and ApoB (r = 0.705) (P < 0.001). Milk PL decreased chylomicron content in total SM and C24:1 Cer (P_group < 0.001), parallel to a marked increase in total Cer in feces (P_group < 0.001). Milk PL modulated some specific SM and Cer species in both ileal efflux and feces, suggesting differential absorption and metabolization processes in the gut.

CONCLUSION

Milk PL supplementation decreased atherogenic SM and Cer species associated with the improvement of cardiovascular risk markers. Our findings bring insights on sphingolipid metabolism in the gut, especially Cer, as signaling molecules potentially participating in the beneficial effects of milk PL.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02099032, NCT02146339.

FUNDING

ANR-11-ALID-007-01; PHRCI-2014: VALOBAB, no. 14-007; CNIEL; GLN 2018-11-07; HCL (sponsor).

Broad Diversity of Near-Infrared Single-Photon Emitters in Silicon

We report the detection of individual emitters in silicon belonging to seven different families of optically active point defects. These fluorescent centers are created by carbon implantation of a commercial silicon-on-insulator wafer usually employed for integrated photonics. Single photon emission is demonstrated over the 1.1-1.55  μm range, spanning the O and C telecom bands. We analyze their photoluminescence spectra, dipolar emissions, and optical relaxation dynamics at 10 K. For a specific family, we show a constant emission intensity at saturation from 10 K to temperatures well above the 77 K liquid nitrogen temperature. Given the advanced control over nanofabrication and integration in silicon, these individual artificial atoms are promising systems to investigate for Si-based quantum technologies.

Sulfonimides versus ketosulfonamides as epoxidized imidazolium counterions: towards a new generation of ionic liquid monomers

Ionic liquid monomers with various sulfonimides or ketosulfonamides as unprecedented counteranions of imidazolium ILs were submitted to the Prilezhaev reaction and the intrinsic properties of these new epoxy monomers was unveiled.

ANT2-Mediated ATP Import into Mitochondria Protects against Hypoxia Lethal Injury

Following a prolonged exposure to hypoxia–reoxygenation, a partial disruption of the ER-mitochondria tethering by mitofusin 2 (MFN2) knock-down decreases the Ca²⁺ transfer between the two organelles limits mitochondrial Ca²⁺ overload and prevents the Ca²⁺-dependent opening of the mitochondrial permeability transition pore, i.e., limits cardiomyocyte cell death. The impact of the metabolic changes resulting from the alteration of this Ca²⁺crosstalk on the tolerance to hypoxia–reoxygenation injury remains partial and fragmented between different field of expertise. >In this study, we report that MFN2 loss of function results in a metabolic switch driven by major modifications in energy production by mitochondria. During hypoxia, mitochondria maintain their ATP concentration and, concomitantly, the inner membrane potential by importing cytosolic ATP into mitochondria through an overexpressed ANT2 protein and by decreasing the expression and activity of the ATP hydrolase via IF1. This adaptation further blunts the detrimental hyperpolarisation of the inner mitochondrial membrane (IMM) upon re-oxygenation. These metabolic changes play an important role to attenuate cell death during a prolonged hypoxia–reoxygenation challenge.

Human milk pasteurisation reduces pre-lipolysis but not digestive lipolysis and moderately decreases intestinal lipid uptake in a combination of preterm infant in vitro models

Donor human milk, pasteurised for safety reasons, is the first alternative for feeding preterm infants when mothers' own milk is unavailable. Breastmilk pasteurisation impact on lipid digestion and absorption was evaluated by a static in vitro digestion model for preterm infants coupled with intestinal absorption using Caco-2/TC7 cells. Lipid absorption was quantified by digital image analysis of lipid droplets, by measurement of basolateral triglyceride concentration and by analysing the expression of major genes involved. After in vitro digestion, lipolysis extent was 13% lower in pasteurised human milk (PHM) than in raw human milk (RHM). In Caco-2/TC7 cells, the number of lipid droplets was identical for both milk types, while the mean droplet area was 17% smaller with PHM. Altogether, pasteurisation decreased the pre-lipolysis of human milk. This initial difference in free fatty acid amount was only partially buffered by the subsequent processes of in vitro digestion and cellular lipid absorption.

Bis(monoacylglycero)phosphate, a new lipid signature of endosome-derived extracellular vesicles

Bis(monoacylglycero)phosphate (BMP), also known as lysobisphosphatidic acid (LBPA), is a phospholipid specifically enriched in the late endosome-lysosome compartment playing a crucial role for the fate of endocytosed components. Due to its presence in extracellular fluids during diseases associated with endolysosomal dysfunction, it is considered as a possible biomarker of disorders such as genetic lysosomal storage diseases and cationic amphiphilic drug-induced phospholipidosis. However, there is no true validation of this biomarker in human studies, nor a clear identification of the carrier of this endolysosome-specific lipid in biofluids. The present study demonstrates that in absence of any sign of renal failure, BMP, especially all docosahexaenoyl containing species, are significantly increased in the urine of patients treated with the antiarrhythmic drug amiodarone. Such urinary BMP increase could reflect a generalized drug-induced perturbation of the endolysosome compartment as observed in vitro with amiodarone-treated human macrophages. Noteworthy, BMP was associated with extracellular vesicles (EVs) isolated from human urines and extracellular medium of human embryonic kidney HEK293 cells and co-localizing with classical EV protein markers CD63 and ALIX. In the context of drug-induced endolysosomal dysfunction, increased BMP-rich EV release could be useful to remove excess of undigested material. This first human pilot study not only reveals BMP as a urinary biomarker of amiodarone-induced endolysosomal dysfunction, but also highlights its utility to prove the endosomal origin of EVs, also named as exosomes. This peculiar lipid already known as a canonical late endosome-lysosome marker, may be thus considered as a new lipid marker of urinary exosomes.

Photolytic degradation of molecular iodine adsorbed on model SiO2 particles

A molecular derivatization method followed by gas chromatographic separation coupled with mass spectrometric detection was used to study photolytic degradation of I₂ adsorbed on solid SiO₂ particles. This heterogeneous photodegradation of I₂ is studied at ambient temperature in synthetic air to better understand I₂ atmospheric dispersion and environmental fate. The obtained laboratory results show a considerably enhanced atmospheric lifetime of molecular iodine adsorbed on solid media. The heterogeneous atmospheric residence time (τ) of I₂ is calculated to be τ ≈ 187 min, i.e., τ ≈ 3 h. The obtained heterogeneous lifetime of I₂ is shown to be considerably longer than its destruction by its principal atmospheric sink, namely, photolysis. The observed enhanced atmospheric lifetime of I₂ on heterogeneous media will likely have direct consequences on the atmospheric transport of I₂ that influences the toxicity or the oxidative capacity of the atmosphere.

Impact of malpractice liability among spine surgeons: A national survey of French private neurosurgeons

PURPOSE

In the general context of medical judicialization, spine surgeons are impacted by the part that medical responsibility and the risk of malpractice play in their actions and decisions. Our aim was to evaluate possible shifts in practices among private neurosurgeons who are highly exposed to this judicial risk and detect alterations in their pleasure in exercising their profession. We present the first national survey on French physicians' perception of surgical judicialization and consequences on their practice.

METHODS

An online survey was submitted to the 121 members of the French Society of Private Neurosurgery, who represent 29.1% of the total number of spine surgeons and perform 36.0% of the national total spine surgery activity. The French law (no-fault out-of-court scheme) significantly impacts these surgeons in the event of litigation.

RESULTS

A total of 78 surveys were completed (64.5% response rate): 89.7% of respondents experienced alteration of doctor-patient relationship related to judicialization and 60.2% had already refused to perform risky surgeries. Fear of being sued added negative pressure during surgery for 55.1% of respondents and 37.2% of them had already considered stopping their practice because of this litigation context.

CONCLUSION

The increasing impact of medical liability is prompting practitioners to change their practice and perceptions. The doctor-patient relationship appears to be altered, negative pressure is placed on physicians and defensively, some neurosurgeons may refuse high-risk patients and procedures. This situation causes professional disenchantment and can ultimately prove disadvantageous for both doctors and patients.

[Causes, diagnosis and treatments of circulatory shocks]

Shock states are the leading causes of intensive care admission and are nowadays associated with high morbidity and mortality. They are driven by a complex physiopathology and most frequently a multifactorial mechanism. They can be separated in whether a decrease of oxygen delivery (quantitative shock) or an abnormal cell distribution of cardiac output (distributive shock). Septic, cardiogenic and hypovolemic shocks represent more than 80% of shock etiologies. Clinical presentation is mostly characterized by frequent arterial hypotension and sign of poor clinical perfusion. Hyperlactatemia occurs in most of shock states. The diagnostic of shock or earlier reversible "pre-shock" states is urgent in order to initiate adequate therapy. Therefore, orientation and therapies must be discussed with intensive care physiologists in a multidisciplinary approach. Etiologic investigation and correction is a primary concern. Hemodynamic and respiratory support reflect another part of initial therapy toward normalization of cell oxygenation. Fluid resuscitation is the corner stone part of initial therapy of any form of shock. Vasoconstrictive drugs or inotropic support still often remain necessary. The primary goal of initial resuscitation should be not only to restore blood arterial pressure but also to improve clinical perfusion markers. On the biological side, decrease of lactate concentration is associated with better outcome.

Homogeneous triacylglycerol tracers have an impact on the thermal and structural properties of dietary fat and its lipolysis rate under simulated physiological conditions

Dietary fats are present in the diet under different types of structures, such as spread vs emulsions (notably in processed foods and enteral formula), and interest is growing regarding their digestion and intestinal absorption. In clinical trials, there is often a need to add stable isotope-labeled triacylglycerols (TAGs) as tracers to the ingested fat in order to track its intestinal absorption and further metabolic fate. Because most TAG tracers contain saturated fatty acids, they may modify the physicochemical properties of the ingested labeled fat and thereby its digestion. However, the actual impact of tracer addition on fat crystalline properties and lipolysis by digestive lipases still deserves to be explored. In this context, we monitored the thermal and polymorphic behavior of anhydrous milk fat (AMF) enriched in homogeneous TAGs tracers and further compared it with the native AMF using differential scanning calorimetry and power X-ray diffraction. As tracers, we used a mixture of tripalmitin, triolein and tricaprylin at 2 different concentrations (1.5 and 5.7 wt%, which have been used in clinical trials). The addition of TAG tracers modified the AMF melting profile, especially at the highest tested concentration (5.7 wt%). Both AMF and AMF enriched with 1.5 wt% tracers were completely melted around 37 °C, i.e. close to the body temperature, while the AMF enriched with 5.7 wt% tracers remained partially crystallized at this temperature. Similar trends were observed in both bulk and emulsified systems. Moreover, the kinetics of AMF polymorphic transformation was modified in the presence of tracers. While only β' form was observed in the native AMF, the β-form was clearly detected in the AMF containing 5.7 wt% tracers. We further tested the impact of tracers on the lipolysis of AMF in bulk using a static in vitro model of duodenal digestion. Lipolysis of AMF enriched with 5.7 wt% tracers was delayed compared with that of AMF and AMF enriched with 1.5 wt% tracers. Therefore, low amounts of TAG tracers including tripalmitin do not have a high impact on fat digestion, but one has to be cautious when using higher amounts of these tracers.

OS8.4 Impact of brain invasion assessment on outcome in intracranial grade II meningiomas

BACKGROUND

Brain invasion has already been identified as an independent criterion of meningioma recurrence by Jääskaläinen’s in 1986. While it was only suggested that meningiomas harbouring brain invasion could be staged as grade II in the 2007 WHO Classification of Tumours of the Central Nervous System, brain invasion was clearly listed as a grade II atypical meningioma criterion for the first time in the 2016 version. Since 2007, brain invasion has been carefully screened during the histopathological characterisation of meningiomas in our centre thanks to specific training of the neuropathology department staff. Furthermore, neurosurgeons are asked to provide well-preserved and grossly orientable tumours borders whenever possible. The aim of the present study was to compare the characteristics of patients diagnosed with grade II meningiomas before and after this change of practices.

MATERIAL AND METHODS

We retrospectively reviewed the characteristics of 125 patients with grade II meningiomas diagnosed between 2011 and 2014 (group A) and compared them to those of 166 patients with grade II meningiomas diagnosed between 1998 and 2005 (group B).

RESULTS

Tumour location and socio-demographic parameters were comparable in group A and B with a median age of 62 years in both groups (p=0.18). There were more de novo meningiomas in group A (84% vs 68.7%, p=0.004). Brain invasion was found in 59% in group A and 9% in group B (p=0.00001) while median Ki67 labelling was of 8.4% in group A and 10.5% in group B (p=0.04). Consistently, tumour borders were irregular in 52% in group A and 29% in group B (p=0.0002). Progression free survival was similar in the two groups (65 vs 66 months, p=0.92) but grade progression was more frequently observed in group B (18.9% vs 0%, p=0.006). In group A, meningiomas that were classified as grade II exclusively based on brain infiltration (n=33, group A-bi) had a similar progression rate compared to meningiomas with other criteria of atypia (27% vs 25%, p=0.98) and a similar time to progression (32 vs 32 months, p=0.74). The median time to progression of group A-bi meningiomas was also comparable to that of the other 258 pooled meningiomas (32 vs 40 months, p=0.40).

CONCLUSION

In accordance with the 2016 WHO Classification of Tumours of the Central Nervous System, the outcome of meningiomas defined as atypical solely based on brain infiltration seems to be comparable to that of meningiomas with other criteria of atypia. Appropriate coordination between neurosurgeons and neuropathologists is mandatory to optimally assess this criterion.

Metabolic effects in mice of cream formulation: Addition of both thickener and emulsifier does not alter lipid metabolism but modulates mucus cells and intestinal endoplasmic reticulum stress

Additives stabilize or improve the organoleptic or functional properties (or both) of many dairy products including whipping cream. Their influence on the metabolic effect of dairy cream is scarcely known. We tested the hypothesis that added emulsifier (lactic acid esters of mono- and diglycerides; MAG/DAG), thickener (carrageenan, CGN), or both, could modify the metabolic effect, notably in the intestine and liver. Nine-week-old male C57Bl/6J mice were fed UHT cream (indirect treatment) mixed with nonlipidic powder (final: 13% milkfat) for 1 or 4 wk. We compared creams (1) without additive (Ctl), (2) with thickener (Th), 0.02% of κ-CGN, and (3) with both thickener and emulsifier, 0.1% of MAG/DAG esters (Th/Em). We analyzed plasma parameters, intestine, and liver. Fasting glycemia, insulinemia, triglyceridemia, nonesterified fatty acids, body weight gain, and liver weight did not differ among groups. After 1 wk, Th/Em had higher expression in the duodenum of some of the genes involved in (1) intestinal lipid absorption and (2) tight junction proteins versus Ctl and Th. After 4 wk, mucus cell number in the small intestine was higher in Th/Em versus Ctl and Th. Genes involved in endoplasmic reticulum (ER) stress in the duodenum were more expressed in Th/Em after 1 wk. After 4 wk, in the colon, a higher expression of ER stress genes was observed for Th versus Th/Em and Ctl. Liver damage score was not altered by additives. Adding both CGN (0.02%) and MAG/DAG esters (0.1%) in dairy cream did not result in deleterious outcomes in mice after 4 wk regarding lipid metabolism, intestinal permeability, and liver disorders. The longer term effect of intestinal ER stress modulation deserves further investigation.

Metabolic effects in mice of cream processing: Direct ultra-high-temperature process lowers high-fat-induced adipose tissue inflammation

Although UHT heat treatment is being optimized to improve the stability and functional properties of dairy products, its metabolic effects remain scarcely known. As such, we studied the effect of the type of UHT process on lipid metabolism, intestinal barrier, and inflammation in mice. Nine-week-old male C57Bl/6J mice were fed a diet composed of nonlipidic powder mixed with different UHT dairy creams (final: 13% milkfat) for 1 or 4 wk. All creams contained 0.02% of thickener (carrageenan) and were treated via either (1) classical indirect heating process (Th), (2) indirect process at higher temperature (Th+), or (3) direct process by steam injection (ThD). Plasma, epididymal adipose tissue (EAT), and intestine were analyzed. Multivariate principal component analyses were used to identify differential effects of processes. Th+ differed by a globally higher liver damage score compared with that of the other creams. After 4 wk, the duodenal expression of lipid absorption genes fatty acid binding protein 4 (Fatp4) and microsomal triglycerides transfer protein (Mttp) was lower in the Th+ versus Th group. Expression in the colon of tight junction protein zonula occludens 1 (Zo1) and of some endoplasmic reticulum stress markers was lower in both Th+ and ThD versus the Th group. In EAT, ThD had lower gene expression of several inflammatory markers after 4 wk. Some differential effects may be related to heat-induced physicochemical changes of creams. The type of cream UHT process differentially affected metabolic parameters in mice after a 4-wk fat-rich diet, partly due to cream structure. Altogether, direct steam injection process induced the lowest early markers of high-fat-induced metabolic inflammation in EAT.

Soybean polar lipids differently impact adipose tissue inflammation and the endotoxin transporters LBP and sCD14 in flaxseed vs. palm oil-rich diets

Obesity and type 2 diabetes are nutritional pathologies, characterized by a subclinical inflammatory state. Endotoxins are now well recognized as an important factor implicated in the onset and maintain of this inflammatory state during fat digestion in high-fat diet. As a preventive strategy, lipid formulation could be optimized to limit these phenomena, notably regarding fatty acid profile and PL emulsifier content. Little is known about soybean polar lipid (SPL) consumption associated to oils rich in saturated FA vs. anti-inflammatory omega-3 FA such as α-linolenic acid on inflammation and metabolic endotoxemia. We then investigated in mice the effect of different synthetic diets enriched with two different oils, palm oil or flaxseed oil and containing or devoid of SPL on adipose tissue inflammation and endotoxin receptors. In both groups containing SPL, adipose tissue (WAT) increased compared with groups devoid of SPL and an induction of MCP-1 and LBP was observed in WAT. However, only the high-fat diet in which flaxseed oil was associated with SPL resulted in both higher WAT inflammation and higher circulating sCD14 in plasma. In conclusion, we have demonstrated that LPS transporters LBP and sCD14 and adipose tissue inflammation can be modulated by SPL in high fat diets differing in oil composition. Notably high-flaxseed oil diet exerts a beneficial metabolic impact, however blunted by PL addition. Our study suggests that nutritional strategies can be envisaged by optimizing dietary lipid sources in manufactured products, including fats/oils and polar lipid emulsifiers, in order to limit the inflammatory impact of palatable foods.

Disruption of calcium transfer from ER to mitochondria links alterations of mitochondria-associated ER membrane integrity to hepatic insulin resistance

AIMS/HYPOTHESIS

Mitochondria-associated endoplasmic reticulum membranes (MAMs) are regions of the endoplasmic reticulum (ER) tethered to mitochondria and controlling calcium (Ca(2+)) transfer between both organelles through the complex formed between the voltage-dependent anion channel, glucose-regulated protein 75 and inositol 1,4,5-triphosphate receptor (IP3R). We recently identified cyclophilin D (CYPD) as a new partner of this complex and demonstrated a new role for MAMs in the control of insulin's action in the liver. Here, we report on the mechanisms by which disruption of MAM integrity induces hepatic insulin resistance in CypD (also known as Ppif)-knockout (KO) mice.

METHODS

We used either in vitro pharmacological and genetic inhibition of CYPD in HuH7 cells or in vivo loss of CYPD in mice to investigate ER-mitochondria interactions, inter-organelle Ca(2+) exchange, organelle homeostasis and insulin action.

RESULTS

Pharmacological and genetic inhibition of CYPD concomitantly reduced ER-mitochondria interactions, inhibited inter-organelle Ca(2+) exchange, induced ER stress and altered insulin signalling in HuH7 cells. In addition, histamine-stimulated Ca(2+) transfer from ER to mitochondria was blunted in isolated hepatocytes of CypD-KO mice and this was associated with an increase in ER calcium store. Interestingly, disruption of inter-organelle Ca(2+) transfer was associated with ER stress, mitochondrial dysfunction, lipid accumulation, activation of c-Jun N-terminal kinase (JNK) and protein kinase C (PKC)ε and insulin resistance in liver of CypD-KO mice. Finally, CYPD-related alterations of insulin signalling were mediated by activation of PKCε rather than JNK in HuH7 cells.

CONCLUSIONS/INTERPRETATION

Disruption of IP3R-mediated Ca(2+) signalling in the liver of CypD-KO mice leads to hepatic insulin resistance through disruption of organelle interaction and function, increase in lipid accumulation and activation of PKCε. Modulation of ER-mitochondria Ca(2+) exchange may thus provide an exciting new avenue for treating hepatic insulin resistance.

Dietary emulsifiers from milk and soybean differently impact adiposity and inflammation in association with modulation of colonic goblet cells in high-fat fed mice

SCOPE

Enhanced adiposity and metabolic inflammation are major features of obesity that could be impacted by dietary emulsifiers. We investigated in high-fat fed mice the effects of using a new polar lipid (PL) emulsifier from milk (MPL) instead of soybean lecithin (soybean PL [SPL]) on adipose tissue and intestinal mucosa function.

METHODS AND RESULTS

Four groups of C57BL6 mice received for 8 wks a low-fat (LF) diet or a high-fat diet devoid of PLs or an high-fat diet including MPL (high-fat-MPL) or SPL (high-fat-SPL). Compared with high-fat diet, high-fat-SPL diet increased white adipose tissue (WAT) mass (p < 0.05), with larger adipocytes (p < 0.05) and increased expression of tumor necrosis factor alpha, monochemoattractant protein-1, LPS-binding protein, and leptin (p < 0.05). This was not observed with high-fat-MPL diet despite similar dietary intakes and increased expression of fatty acid transport protein 4 and microsomal TG transfer protein, involved in lipid absorption, in upper intestine (p < 0.05). High-fat-MPL mice had a lower expression in WAT of cluster of differentiation 68, marker of macrophage infiltration, versus high-fat and high-fat-SPL mice (p < 0.05), and more goblet cells in the colon (p < 0.05).

CONCLUSIONS

Unlike SPL, MPL in the high-fat diet did not induce WAT hypertrophy and inflammation but increased colonic goblet cells. This supports further clinical exploration of different sources of dietary emulsifiers in the frame of obesity outbreak.

Computed tomography and magnetic resonance diagnosis of variations in the anatomical location of the major salivary glands in 1680 dogs and 187 cats

During assessment of routine clinical magnetic resonance imaging (MRI) of the heads of dogs, variations in the location of mandibular and zygomatic salivary glands (SGs) were observed incidentally. The aims of this retrospective study were to describe anatomical variations of the major SGs found on MRI and computed tomography (CT) studies of the head in dogs and cats and to investigate possible clinical relevancy. No anatomical variation of the SGs was seen in cats, but in dogs, although variation of the parotid SG was not identified, that of the mandibular SG was found in 33/1680 animals (2%), either unilaterally (6/33 right-sided, 13/33 left-sided) or bilaterally (14/33). The Border terrier breed (19/33, 58%) was over-represented. Each atypically located mandibular SG was positioned medial to the digastric muscle and rostral to the retropharyngeal lymph node. The sublingual glands were difficult to delineate from the mandibular glands. Anatomical variation of one zygomatic gland (3/4 left-sided) was identified in four small-breed dogs (0.2%). Each atypically located zygomatic gland was tilted at the ventrorostral aspect of the masseter muscle underneath the skin surface. MRI and CT characteristics were not different between typically and atypically located SGs. None of the dogs had clinical signs related with SG disease. It was concluded that, with suspected breed predispositions, incidental unilateral or bilateral anatomical variations of mandibular and zygomatic SGs can be encountered in dogs and an awareness of these possible variations may be important in pre-surgical planning.

Giant and complex aneurysms treatment with preservation of flow via bypass technique

Due to their anatomical characteristics and the complexity of the procedures required to obtain their complete occlusion, the treatment of giant intracranial aneurysms is a real challenge. Direct reconstructive strategies, whether by interventional neuroradiology (coils, stents) or microsurgical (clipping) means, are not always applicable and, in patients that would not tolerate parent or collateral artery sacrifice, the adjunction of a revascularization procedure using a bypass technique might be necessary. Cerebral arterial bypasses can be classified according to their function (3 types: flow replacement, flow reversal or protective), the branching mode of the graft used (3 types: pedicled, interpositional or in situ), the sites of anastomosis (2 types: extracranial-intracranial or intracranial-intracranial) and the class of flow they are supposed to provide (3 types: low-, intermediate- or high-flow). In this article, the authors review the different aspects in the management of patients with a giant intracranial aneurysm using a bypass: preoperative work-up, types of bypass and indications, surgical techniques and results.

Imeglimin normalizes glucose tolerance and insulin sensitivity and improves mitochondrial function in liver of a high-fat, high-sucrose diet mice model

Imeglimin is the first in a new class of oral glucose-lowering agents currently in phase 2b development. Although imeglimin improves insulin sensitivity in humans, the molecular mechanisms are unknown. This study used a model of 16-week high-fat, high-sucrose diet (HFHSD) mice to characterize its antidiabetic effects. Six-week imeglimin treatment significantly decreased glycemia, restored normal glucose tolerance, and improved insulin sensitivity without modifying organs, body weights, and food intake. This was associated with an increase in insulin-stimulated protein kinase B phosphorylation in the liver and muscle. In liver mitochondria, imeglimin redirects substrate flows in favor of complex II, as illustrated by increased respiration with succinate and by the restoration of respiration with glutamate/malate back to control levels. In addition, imeglimin inhibits complex I and restores complex III activities, suggesting an increase in fatty acid oxidation, which is supported by an increase in hepatic 3-hydroxyacetyl-CoA dehydrogenase activity and acylcarnitine profile and the reduction of liver steatosis. Imeglimin also reduces reactive oxygen species production and increases mitochondrial DNA. Finally, imeglimin effects on mitochondrial phospholipid composition could participate in the benefit of imeglimin on mitochondrial function. In conclusion, imeglimin normalizes glucose tolerance and insulin sensitivity by preserving mitochondrial function from oxidative stress and favoring lipid oxidation in liver of HFHSD mice.

Evaluation of the ventro 20° rostral-dorsocaudal oblique radiographic projection for the investigation of canine nasal disease

OBJECTIVE

To assess the ventro 20° rostral-dorsocaudal oblique projection for canine nasal disease as an alternative to the dorsoventral intra-oral view.

MATERIALS AND METHODS

Thirty-one dogs with nasal disease underwent radiography and computed tomography with a final diagnosis of underlying cause achieved through rhinoscopy, biopsy or cytology. Three independent observers, blinded to diagnosis, reviewed the nasal radiographs on two separate occasions. Intra- and inter-observer agreement and level of confidence on radiographic diagnosis were evaluated and radiographic diagnosis was compared with computed tomography and definitive diagnosis.

RESULTS

The ventro 20° rostral-dorsocaudal oblique projection of canine nasal cavities was feasible in anaesthetised dogs and gave diagnostic quality images in most dogs. Assessment of this view showed moderate to substantial agreement with computed tomography diagnosis but gave lower confidence in diagnosis. Interpretation of this radiographic projection had substantial to almost perfect repeatability but moderate reproducibility.

CLINICAL SIGNIFICANCE

The ventro 20° rostral-dorsocaudal oblique projection may be used as a valuable initial screening tool for canine nasal pathology in practices without access to advanced imaging, although computed tomography is still likely to provide greater diagnostic information.