Assessing Spns2-dependent S1P Transport as a Prospective Therapeutic Target.

S1P (sphingosine 1-phosphate) receptor modulator (SRM) drugs interfere with lymphocyte trafficking by downregulating lymphocyte S1P receptors. While the immunosuppressive activity of SRM drugs has proved useful in treating autoimmune diseases such as multiple sclerosis, that drug class is beset by on-target liabilities such as initial dose bradycardia. The S1P that binds to cell surface lymphocyte S1P receptors is provided by S1P transporters. Mice born deficient in one of these, spinster homolog 2 (Spns2), are lymphocytopenic and have low lymph S1P concentrations. Such observations suggest that inhibition of Spns2-mediated S1P transport might provide another therapeutically beneficial method to modulate immune cell positioning. We report here results using a novel S1P transport blocker (STB), SLF80821178, to investigate the consequences of S1P transport inhibition in rodents. We found that SLF80821178 is efficacious in a multiple sclerosis model but - unlike the SRM fingolimod - neither decreases heart rate nor compromises lung endothelial barrier function. Notably, although Spns2 null mice have a sensorineural hearing defect, mice treated chronically with SLF80821178 have normal hearing acuity. STBs such as SLF80821178 evoke a dose-dependent decrease in peripheral blood lymphocyte counts, which affords a reliable pharmacodynamic marker of target engagement. However, the maximal reduction in circulating lymphocyte counts in response to SLF80821178 is substantially less than the response to SRMs such as fingolimod (50% vs. 90%) due to a lesser effect on T lymphocyte sub-populations by SLF80821178. Finally, in contrast to results obtained with Spns2 deficient mice, lymph S1P concentrations were not significantly changed in response to administration of STBs at doses that evoke maximal lymphopenia, which indicates that current understanding of the mechanism of action of S1P transport inhibitors is incomplete.

Cervical approach for prestyloid parapharyngeal pleomorphic adenoma resection.

OBJECTIVE: To describe the key points of cervical resection for prestyloid parapharyngeal pleomorphic adenoma and to discuss the role of modern imaging. OBSERVATION: Retrospective case series of 10 patients (4 women and 6 men, age 29-63 years) with prestyloid parapharyngeal pleomorphic adenoma with 2 to 8cm largest diameter on MRI, consecutively resected via a cervical approach between 2000 and 2020 in a French tertiary university referral care center. Seven patients had a minimum 10 years' follow-up, and one was lost to follow-up before the fifth postoperative year. Peri- and postoperative complications comprised great auricular nerve transection without subsequent symptomatic neuroma (2 patients), associated transoral approach to free the upper pole of the adenoma (2 patients), capsule effraction (3 patients), and hematoma (1 patient). There were no cases of facial paresis or palsy, other cranial nerve impairment, trismus, auriculotemporal or first-bite syndrome. One of the three patients with capsule effraction showed local recurrence at month 17. CONCLUSION: In agreement with previous reports, the present case series confirmed the role of the cervical approach to resect prestyloid parapharyngeal pleomorphic adenoma, and hence the need to continue teaching it.

Positive predictive values of MRI and ultrasound-guided fine-needle aspiration biopsy for isolated parotid swelling in adults: A STARD comparative analysis.

OBJECTIVES: To evaluate positive predictive values (PPVs) of magnetic resonance imaging (MRI) and ultrasound-guided fine-needle aspiration biopsy (UFNAB) in patients with isolated parotid swelling. MATERIAL AND METHODS: Observational study following the STARD guideline, based on a cohort of 212 patients from 18 to 93years of age, with isolated parotid swelling (malignant: 16.9%; benign: 83.1%), consecutively operated on between 2015 and 2020, after work-up including MRI and UFNAB in an otorhinolaryngology department of a university hospital. The main endpoint was PPV for diagnosis of benign tumor, malignant tumor and the most frequent etiology. Secondary endpoints were correlations between PPVs and clinical factors for malignancy, and the impact on PPV of various situations: dynamic analysis on MRI; diagnostic disagreement between MRI and UFNAB; and UFNAB PPV according to MRI diagnosis. RESULTS: PPVs for MRI and UFNAB were respectively 45.4% and 88.8% for malignant tumor, 89.6% and 46.9% for benign tumor, and 88.1% and 85.2% for pleomorphic adenoma (the most frequent etiology). Tumor fixation and history of head and neck radiation therapy PPVs were the only one higher than the MRI one for malignant tumor. MRI PPV did not differ between groups with or without dynamic analysis. PPV for malignant tumor, benign tumor and pleomorphic adenoma on MRI and UFNAB was respectively 42.8% and 33.3%, 42.8% and 100%, and 36.3% and 50% in case of diagnostic discordance. When MRI suggested malignant tumor, UFNAB PPV was 51.8% for malignant tumor, 67.7% for benign tumor, and 37.5% for pleomorphic adenoma; when MRI suggested benign tumor, it was 32.2% for malignant tumor, 91.5% for benign tumor, and 88.5% for pleomorphic adenoma; and, when MRI suggested pleomorphic adenoma, it was 23.5% for malignant tumor, 93.9% for benign tumor, and 92% for pleomorphic adenoma. CONCLUSION: Systematic association of UFNAB to MRI did not fundamentally improve diagnostic accuracy. UFNAB appeared most valuable in case of history of radiation therapy, in case of tumor fixation, and when MRI diagnosis was uncertain and/or suggested malignant tumor and/or the apparent diffusion coefficient (ADC) was low. The contribution of UFNAB when MRI suggested benign tumor or especially pleomorphic adenoma was more limited.

Influence of HLA-C environment on the spontaneous clearance of hepatitis C in European HIV-HCV co-infected individuals.

Natural killer (NK) cell functions are regulated by diverse inhibitory and activating receptors, including killer cell immunoglobulin-like receptors (KIR), which interact with human leukocyte antigen (HLA) class I molecules. Some KIR/HLA genetic combinations were reported associated with spontaneous clearance (SC) of hepatitis C virus (HCV) but with discordant results, possibly reflecting KIR and/or HLA gene polymorphism according to populations. KIR/HLA genetic combinations associated with both an exhaustive NK and T cell repertoire were investigated in a cohort of HIV-HCV co-infected individuals with either SC (n = 68) or chronic infection (CI, n = 163) compared to uninfected blood donors [controls (Ctrl), n = 100]. Multivariate analysis showed that the HLA C2C2 environment was associated with SC only in European HIV-HCV co-infected individuals [odds ratio (OR) = 4·30, 95% confidence interval = 1·57-12·25, P = 0·005]. KIR2D+ NK cell repertoire and potential of degranulation of KIR2DL1/S1+ NK cells were similar in the SC European cohort compared to uninfected individuals. In contrast, decreased frequencies of KIR2DS1+ and KIR2DL2+ NK cells were detected in the CI group of Europeans compared to SC and a decreased frequency of KIR2DL1/S1+ NK cells compared to controls. Regarding T cells, higher frequencies of DNAX accessory molecule-1 (DNAM-1)+ and CD57+ T cells were observed in SC in comparison to controls. Interestingly, SC subjects emphasized increased frequencies of KIR2DL2/L3/S2+ T cells compared to CI subjects. Our study underlines that the C2 environment may activate efficient KIR2DL1+ NK cells in a viral context and maintain a KIR2DL2/L3/S2+ mature T cell response in the absence of KIR2DL2 engagement with its cognate ligands in SC group of HCV-HIV co-infected European patients.

Compliance with antibiotic prophylaxis guidelines in surgery: Results of a targeted audit in a large-scale region-based French hospital network.

INTRODUCTION: While regional monitoring of antibiotic use has decreased since 2011 by 3.2%, in some healthcare facilities a significant increase (+43%) has occurred. The purpose of this study was to assess regional antibiotic prophylaxis (ABP) compliance with national guidelines. MATERIAL AND METHODS: In 2015, 26 healthcare facilities, both public and private, were requested to audit five items: utilization of antibiotic prophylaxis, the antimicrobial agent (the molecule) administered, time between injection and incision, initial dose, number of intraoperative and postoperative additional doses. Seven surgical procedures were selected for assessment: appendicectomy (APP), cataract (CAT), cesarean section (CES), colorectal cancer surgery (CCR), hysterectomy (HYS), total hip arthroplasty (THA) and transurethral resection of the prostate (TURP). A statistical analysis of the 2303 records included was carried out. RESULTS: The general rate of antibiotic prophylaxis compliance was 64%. The antimicrobial agent used and initial dose were in compliance with the guidelines for 93% and 97.4% of cases respectively, and administration of antibiotic prophylaxis was achieved 60minutes before incision in 77.6% of the records included. Regarding gastrointestinal surgery, amoxicillin/clavulanic acid was used in 32% of patients. In 26% of appendectomy files, administration occurred after incision, and one out of two files showed non-complaint perioperative and postoperative consumption. CONCLUSION: Compliance with nationwide ABP guidelines is in need of pronounced improvement, especially with regard to time interval between injection and incision and the molecule prescribed. An action plan based on specific recommendations addressed to each establishment and an updated regionwide ABP protocol are aimed at achieving better and reduced consumption of antimicrobial agents.

3D-printed face protective shield in interventional radiology: Evaluation of an immediate solution in the era of COVID-19 pandemic.

PURPOSE: The purpose of this study was to report the clinical evaluation of a 3D-printed protective face shield designed to protect interventional radiologists from droplet transmission of the SARS-Cov-2. MATERIALS AND METHODS: A protective face shield consisting in a standard transparent polymerizing vinyl chloride (PVC) sheet was built using commercially available 3D printers. The 3D-printed face shield was evaluated in 31 interventional procedures in terms of ability to perform the assigned intervention as usual, quality of visual comfort and tolerance using a Likert scale (from 1, as very good to 5, as extremely poor). RESULTS: The mean rating for ability to perform the assigned intervention as usual was 1.7±0.8 (SD) (range: 1-4). The mean visual tolerance rating was 1.6±0.7 (SD) (range: 1-4). The mean tolerability rating was 1.4±0.7 (SD) (range: 1-3). CONCLUSION: The 3D-printed protective face shield is well accepted in various interventions. It may become an additional option for protection of interventional radiologists.

[Basal ganglia calcification]. / Calcifications des noyaux gris centraux.

Calcifications of the basal ganglia are frequently seen on the cerebral CT scans and particularly in the globus pallidus. Their frequency increases physiologically with age after 50 years old. However, pathological processes can also be associated with calcium deposits in the gray nuclei, posterior fossa or white matter. Unilateral calcification is often related to an acquired origin whereas bilateral ones are mostly linked to an acquired or genetic origin that will be sought after eliminating a perturbation of phosphocalcic metabolism. In pathological contexts, these calcifications may be accompanied by neurological symptoms related to the underlying disease: Parkinson's syndrome, psychiatric and cognitive disorders, epilepsy or headache. The purpose of this article is to provide a diagnostic aid, in addition to clinical and biology, through the analysis of calcification topography and the study of different MRI sequences.

Retrospective Analysis of Delayed Intraparenchymal Hemorrhage after Flow-Diverter Treatment: Presentation of a Retrospective Multicenter Trial.

BACKGROUND AND PURPOSE: Intracranial aneurysm treatment with flow diverters has shown satisfying results in terms of aneurysm occlusion, and while some cases of delayed intraparenchymal hemorrhage have been described, no systematic analysis of the risk factors affecting its occurrence has been conducted in a large series of patients. This retrospective analysis of delayed intraparenchymal hemorrhage after flow-diverter treatment is a multicenter, retrospective study using a large series of treated patients to analyze factors affecting the occurrence of delayed intraparenchymal hemorrhage. MATERIALS AND METHODS: Patients treated with flow diverters and presenting with delayed intraparenchymal hemorrhage were included from December 2007 to December 2014 in 7 participating centers in France. Patient and aneurysm characteristics were recorded as were characteristics of bleeding (size, lateralization, and time to bleed), treatment, and clinical outcome after 1, 3, and 6 months. RESULTS: Delayed intraparenchymal hemorrhage occurred in 11 patients between 1 and 21 days after the procedure. In 10 of these patients, hemorrhages were ipsilateral to the treated aneurysms. Five of the 11 underwent surgery, and 9 of the 11 had good clinical outcomes at 6 months (mRS ≤2). CONCLUSIONS: The pathogenesis of delayed intraparenchymal hemorrhage occurring after flow-diverter treatment remains unclear. The multidisciplinary management of delayed intraparenchymal hemorrhage yields a relatively low morbidity-mortality rate compared with the initial clinical presentation.

Susceptibility Vessel Sign on MRI Predicts Favorable Clinical Outcome in Patients with Anterior Circulation Acute Stroke Treated with Mechanical Thrombectomy.

BACKGROUND AND PURPOSE: The susceptibility vessel sign on MR imaging has been reported to indicate acute occlusion from erythrocyte-rich thrombus. The purpose of this study was to evaluate the influence of the susceptibility vessel sign seen on MR imaging before treatment on the clinical outcome after mechanical thrombectomy for anterior circulation acute stroke. MATERIALS AND METHODS: We retrospectively included 73 consecutive patients who were treated for anterior circulation acute stroke by mechanical thrombectomy from December 2009 to September 2013. Each patient underwent MR imaging before mechanical thrombectomy. The presence (susceptibility vessel sign+) or absence of the susceptibility vessel sign (susceptibility vessel sign-) was recorded. Mechanical thrombectomy was performed either alone or in association with IV tPA according to the site and time after occlusion. Good functional outcome was defined by an mRS ≤ 2 at 3 months in susceptibility vessel sign+ and susceptibility vessel sign- groups. Patient clinical characteristics, initial NIHSS score and ASPECTS, site of occlusion, time between onset to groin puncture, TICI after mechanical thrombectomy, NIHSS score at day 1, and spontaneous hyperattenuation on CT at day 1 were also analyzed. RESULTS: Fifty-three patients with susceptibility vessel sign+ and 20 with susceptibility vessel sign- were included in our study. mRS ≤ 2 at 3 months occurred in 65% patients in the susceptibility vessel sign+ group and 26% in the susceptibility vessel sign- group (P = .004). On multivariate analysis, the susceptibility vessel sign was the only parameter before treatment that could predict mRS ≤ 2 at 3 months (OR, 8.7; 95% CI, 1.1-69.4; P = .04). CONCLUSIONS: Our study strongly suggests that the susceptibility vessel sign on MR imaging before treatment is predictive of favorable clinical outcome for patients presenting with anterior circulation acute stroke and treated with mechanical thrombectomy.

Facial nerve: from anatomy to pathology.

The facial nerve (CN VII) emerges from the facial nerve nucleus in the pons. It is accompanied by CN VIII along its cisternal pathway, as well as at the internal auditory meatus. Its petrous pathway includes a labyrinthine segment, a horizontal tympanic segment and a vertical mastoid segment until the stylomastoid foramen. It then continues to the parotid gland. Pontine impairment is usually associated with other neurological symptoms. Lesions of the cerebellopontine angle (most often meningioma and schwannoma) initially result in impairment of CN VIII. The impairment of CN VII takes second place. Peripheral impairment (outside of a traumatic context) is most often due to Bell's palsy.

Management of ischemic stroke in the hyperacute phase.

Over the last 15 years, advances in acute ischemic stroke (AIS) management have led to a significant reduction in the morbidity and mortality related to this serious disease. This has resulted from progress in imaging technology, increased access to imaging procedures, enhanced coordination in stroke care from emergency departments to rehabilitation centers, development of organized inpatient stroke units, and to the widespread use of acute thrombolysis. Once the diagnosis of AIS is confirmed by neuroimaging, the etiological work up is conducted in parallel with therapeutic measures by stroke units. The intravenous administration of recombinant tissue plasminogen activator (rt-PA) remains the most beneficial intervention in emergency stroke management, but it must be administered within 4.5 hours following the onset of symptoms and only in eligible patients. Recently, several procedures for increasing the efficacy of arterial recanalization have emerged, including intra-arterial administration of thrombolytic agents, mechanical reopening techniques, development of new thrombolytic agents, protocol modifications that allow treatment beyond 4.5 hours or in individuals >80 years old, and remote patient evaluation via telemedicine. So far, no potentially neuroprotective drug has shown to improve outcome following stroke. In addition, pulmonary status, blood pressure, glucose, temperature, and cardiac function must be closely monitored in patients undergoing treatment for AIS. Complications such as cerebral edema, hemorrhagic transformation, seizure, infection, and venous thromboembolic disease worsen the prognosis, and must be prevented or treated. Like myocardial infarction, ischemic stroke should be considered as a treatable emergency. Widespread public education regarding stroke symptoms, novel treatments, and time constraints for effective therapy should increase the number of patients that present within the first hours after stroke. Since "time is brain," early presentation is key to transforming trial results into effective stroke therapies.

Infectious and metabolic brain imaging.

Central nervous system infectious and metabolic disease is a vast domain. We have chosen to focus particularly on five pathological conditions: brain abscess, herpes encephalitis, Creutzfeldt-Jacob disease, posterior reversible encephalopathy and central pontine myelinolysis. We will pay particular attention to MRI signs and the specific sequences to use in each condition, in addition to the conventional sequences, in order to avoid diagnostic traps. Once the MRI exploration is complete, the diagnosis still cannot be established without knowing the clinical and metabolic context.

Flavour exposures after conditioned aversion or preference trigger different brain processes in anaesthetised pigs.

We describe the behavioural consequences of conditioned flavour aversion and preference in pigs and have investigated the brain circuits involved in the representation of flavours with different hedonic values. The study was performed on eight 30-kg pigs. (i) Animals were negatively conditioned to an F- flavour added to a meal followed by LiCl intraduodenal (i.d.) injection, and positively conditioned to an F+ flavour added to a meal followed by NaCl i.d. injection. F+ and F- were thyme or cinnamon flavours. After each conditioning, the behavioural activities were recorded; (ii) One and 5 weeks later, animals were subjected to three two-choice food tests to investigate their preferences between F+, F- and a novel flavour (O); and (iii) Anaesthetised animals were subjected to three SPECT brain imaging sessions: control situation (no flavour) and exposure to F+ and to F-. The negative reinforcement induced a physical malaise and visceral illness. After a positive reinforcement, animals showed playing or feeding motivation and quietness. F+ was significantly preferred over O and F-, and O was significantly preferred over F-. Both F- and F+ induced some metabolic differences in neural circuits involved in sensory associative processes, learning and memory, emotions, reward and feeding motivation. Exposure to F+ induced a higher activity in corticolimbic and reward-related areas, while F- induced a deactivation of the basal nuclei and limbic thalamic nuclei. This study reveals the unconscious cognitive dimension evoked by food flavours according to the individual experience, and highlights the importance of the food sensory image on hedonism and anticipatory eating behaviour.

Urokinase receptor primes cells to proliferate in response to epidermal growth factor.

Epidermal growth factor (EGF) expresses mitogenic activity by a mechanism that requires the EGF receptor (EGFR). We report that murine embryonic fibroblasts (MEFs) proliferate in response to EGF only when these cells express the urokinase receptor (uPAR). EGFR expression was equivalent in uPAR-/- and uPAR+/+ MEFs. In response to EGF, these cells demonstrated equivalent overall EGFR tyrosine phosphorylation and ERK/MAP kinase activation; however, phosphorylation of Tyr-845 in the EGFR, which has been implicated in cell growth, was substantially decreased in uPAR-/- MEFs. STAT5b activation also was decreased. As Tyr-845 is a c-Src target, we overexpressed c-Src in uPAR-/- MEFs and rescued EGF mitogenic activity. Rescue also was achieved by expressing murine but not human uPAR, suggesting a role for autocrine uPAR cell-signaling. In MDA-MB 231 breast cancer cells, EGF mitogenic activity was blocked by uPAR gene silencing, with antibodies that block uPA-binding to uPAR, and with a synthetic peptide that disrupts uPAR-dependent cell signaling. Again, c-Src overexpression rescued the mitogenic activity of EGF. We conclude that uPAR-dependent cell-signaling may prime cells to proliferate in response to EGF by promoting Tyr-845 phosphorylation and STAT5b activation. The importance of this pathway depends on the c-Src level in the cell.

Xenopus ADAM 13 is a metalloprotease required for cranial neural crest-cell migration.

BACKGROUND: Cranial neural-crest (CNC) cells originate from the lateral edge of the anterior neuroepithelium and migrate to form parts of the peripheral nervous system, muscles, cartilage, and bones of the face. Neural crest-cell migration involves the loss of adhesion from the surrounding neuroepithelium and a corresponding increase in cell adhesion to the extracellular matrix (ECM) present in migratory pathways. While proteolytic activity is likely to contribute to the regulation of neural crest-cell adhesion and migration, the role of a neural crest-specific protease in these processes has yet to be demonstrated. We previously showed that CNC cells express ADAM 13, a cell surface metalloprotease/disintegrin. Proteins of this family are known to act in cell-cell adhesion and as sheddases. ADAMs have also been proposed to degrade the ECM, but this has not yet been shown in a physiological context. RESULTS: Using a tissue transplantation technique, we show that Xenopus CNC cells overexpressing wild-type ADAM 13 migrate along the same hyoid, branchial, and mandibular pathways used by normal CNC cells. In contrast, CNC cell grafts that express protease-defective ADAM 13 fail to migrate along the hyoid and branchial pathways. In addition, ectopic expression of wild-type ADAM 13 results in a gain-of-function phenotype in embryos, namely the abnormal positioning of trunk neural-crest cells. We further show that explanted embryonic tissues expressing wild-type, but not protease-defective, ADAM 13 display decreased cell-matrix adhesion. Purified ADAM 13 can cleave fibronectin, and tissue culture cells that express wild-type, but not protease-defective, ADAM 13 can remodel a fibronectin substrate. CONCLUSIONS: Our findings support the hypothesis that the protease activity of ADAM 13 plays a critical role in neural crest-cell migration along defined pathways. We propose that the ADAM 13-dependent modification of ECM and/or other guidance molecules is a key step in the directed migration of the CNC.

PACSIN2 is a regulator of the metalloprotease/disintegrin ADAM13.

ADAM13 is a cell surface metalloprotease expressed in cephalic neural crest cells during early Xenopus development. The cytoplasmic domain of ADAM13 contains three potential SH3 (Src homology type 3) binding sites, suggesting that this region may support interactions with intracellular proteins. In this report we describe the identification, by a new strategy, of three proteins that bind the ADAM13 cytoplasmic domain in vitro: X-Src1, X-An4, and X-PACSIN2. We focused our study on X-PACSIN2 protein because it colocalizes with ADAM13 in migrating neural crest cells during embryonic development. Using pull-down experiments we show that X-PACSIN2 binds to ADAM13 in vitro. Using Xenopus XTC cells, we demonstrate that ADAM13 and X-PACSIN2 colocalize to membrane ruffles and cytoplasmic vesicles. We also show that X-PACSIN2 overexpression can rescue developmental alterations induced by overexpression of ADAM13, suggesting that both proteins interact in vivo. Finally, our results suggest that X-PACSIN2 overexpression reduces endogenous ADAM13 function while a truncated X-PACSIN2 (DeltaSH3) increases this activity in cephalic neural crest cells. We propose that X-PACSIN2 may regulate ADAM13 activity by influencing either its subcellular localization or its catalytic activity. In agreement with this model, elimination of the ADAM13 cytoplasmic domain increased developmental alterations attributable to ADAM13 proteolytic activity.

Integrins: regulators of embryogenesis.

Integrins are heterodimeric transmembrane glycoproteins involved in cell-cell and cell-extracellular matrix adhesion. They also participate in cytoskeletal rearrangements, co-regulation of growth factor activities and activation of signal transductions. This review describes experimental approaches that have given new insights into the integrin functions during embryogenesis. Using anti-functional antibodies, peptide inhibitors of integrin-ligand interactions and genetic ablation of integrins results, this review will show that integrins are key molecules during early development of both invertebrates and vertebrates.