Effects of Rapamycin on Insulin Brain Endothelial Cell Binding and Blood-Brain Barrier Transport

Rapamycin is an exogenous compound that has been shown to improve cognition in Alzheimer’s disease mouse models and can regulate pathways downstream of the insulin receptor signaling pathway. Insulin is also known to improve cognition in rodent models of Alzheimer’s disease. Central nervous system (CNS) insulin must first cross the blood–brain barrier (BBB), a specialized network of brain endothelial cells. This transport process is regulated by physiological factors, such as insulin itself, triglycerides, cytokines, and starvation. Since rapamycin treatment can alter the metabolic state of rodents, increase the circulating triglycerides, and acts as a starvation mimetic, we hypothesized rapamycin could alter the rate of insulin transport across the BBB, providing a potential mechanism for the beneficial effects of rapamycin on cognition. Using young male and female CD-1 mice, we measured the effects of rapamycin on the basal levels of serum factors, insulin receptor signaling, vascular binding, and BBB pharmacokinetics. We found chronic rapamycin treatment was able to affect basal levels of circulating serum factors and endothelial cell insulin receptor signaling. In addition, while acute rapamycin treatment did affect insulin binding at the BBB, overall transport was unaltered. Chronic rapamycin slowed insulin BBB transport non-significantly (p = 0.055). These results suggest that rapamycin may not directly impact the transport of insulin at the BBB but could be acting to alter insulin signaling within brain endothelial cells, which can affect downstream signaling.

Séroprévalence SARS-Cov-2 chez les professionnels de santé : étude multicentrique avec analyse des facteurs de risque professionnels et extraprofessionnels

Introduction

L’objectif de notre étude était d’évaluer la séroprévalence SARS-Cov-2 chez les professionnels de santé, après la première vague Covid-19, et d’analyser les facteurs professionnels et extraprofessionnels modifiant cette prévalence.

Matériels et méthodes

Suite aux instructions gouvernementales proposant de réaliser une sérologie Covid-19 à tout professionnel de santé après la première vague, nous avons réalisé une étude transversale, multicentrique. Tous les professionnels volontaires des quatre centres participants étaient invités à réaliser une sérologie et à remplir un questionnaire concernant leurs données démographiques, leurs caractéristiques professionnelles, l’utilisation des équipements de protection individuelle et l’exposition extra professionnelle au Covid-19. Nous avons calculé la prévalence SARS-Cov-2 et utilisé une régression logistique en appliquant un effet centre.

Résultats

Un total de 3454 professionnels ont participé à l’étude dont 83,4 % de femmes. L’âge moyen était de 40,6 ans [31,8–50,3]. En médiane, la prévalence sérologique SARS-Cov-2 était de 5 % (95 % IC, 4,3 %–5,8 %). Les facteurs associés à une plus forte séroprévalence étaient : l’âge < 30 ans (aOR = 1,59, (95 % IC, 1,06–2,37)), le statut d’étudiant (aOR = 3,38, (95 % IC, 1,62–7,05)) avec une séroprévalence de 16,9 % dans cette catégorie. L’unité de travail, y compris le fait d’avoir travaillé en unité Covid ou en réanimation, ainsi que l’exposition à des patients (quel que soit leur statut infectieux) n’étaient pas associé à une augmentation de la séroprévalence. Par contre les professionnels rapportant un contact avec un patient Covid, sans protection adaptée, ou ayant pratiqué des taches aérosolisantes, y compris avec un masque FFP2, avaient un surrisque d’infection Covid-19 (respectivement aOR à 1,66 et 1,7). Enfin, l’exposition à un collègue infecté ou à un cas familial était également associée à une augmentation de la prévalence sérologique.

Conclusion

Les mesures mises en place pour limiter la transmission du SARS-Cov-2 des patients aux professionnels de santé semblent efficaces. En complément de la vaccination, l’éviction systématique des professionnels infectés, la formation des étudiants et le rappel des mesures d’hygiène durant les temps de pause pourraient limiter la contamination des professionnels de santé.

Abstract 033: Epigenetic Clocks And Incident Heart Failure: The Atherosclerosis Risk In Communities (aric)

Background: DNA methylation (DNAm)-based measures of aging, termed epigenetic clocks (EC), are associated with aging-related outcomes including cardiovascular disease (CVD) and all-cause mortality. Associations of ECs with heart failure (HF) are unclear. We tested whether ECs were positively associated with risk of incident HF in the Atherosclerosis Risk in Communities (ARIC) study and evaluated whether adding ECs to Pooled Cohort Equation (PCE) variables improved risk prediction.

Methods: We measured DNAm in peripheral blood leukocytes in 2,263 African American (mean age=56.3 years) and 925 European American (mean age=59.5 years) participants using the Illumina HM450K and calculated 7 ECs: Horvath, Hannum, extrinsic (EEAA) and intrinsic (IEAA) epigenetic age acceleration, Hannum, PhenoAge, and GrimAge. HF was ascertained by ICD- 9 code 428 and adjudication by an expert panel. We carried out race stratified proportional hazards regression to test associations ECs with incident HF, adjusting for PCE variables: age, sex, smoking, total cholesterol, HDL, systolic blood pressure (SBP), antihypertensive medication use, and diabetes. We calculated area under the curve (AUC) and integrated discrimination index (IDI) to evaluate improvement in risk prediction when adding the ECs to PCE variables.

Results: The number of incident HF events and mean follow-up time in African Americans and European Americans were 640 (189 in the first 10 years) and 19.3 years, and 191 and 21.7 years, respectively. All 7 ECs were positively associated with HF in both African Americans and European Americans. In African Americans with follow-up restricted to the first 10 years, the HR for a one SD increment in GrimAge (5.64 years) was 1.57 (95% CI=1.31, 1.88), comparable to that for a one-SD (5.82 years) increment in age (HR=1.58, 95% CI=1.36, 1.83) and greater than that for a one-SD (20.2mmHg) increment in SBP (HR=1.33, 95% CI=1.18, 1.51). In European Americans across the entire follow-up period, the HR for a one-SD increment in GrimAge (6.13 years) was 1.22 (95% CI=1.06, 1.41), smaller than that for a one-SD (5.50 years) increment in age (HR=1.93, 95% CI=1.63, 2.29) and larger than that for a one-SD (17.9 mmHG) increment in SBP (HR=1.13, 95% CI=0.98, 1.30). In African Americans with follow-up restricted to the first 10 years, adding GrimAge to PCE variables increased AUC by 0.019 (95% CI=0.003, 0.035) and the IDI was 0.010 (95% CI=0.002, 0.019). In European Americans, adding GrimAge did not change AUC appreciably (0.004, 95% CI=-0.006, 0.014) and the IDI was 0.002 (95% CI=0.000, 0.005).

Conclusion: ECs are positively associated with HF in African American and European American participants independent of traditional CVD risk factors. GrimAge modestly improved heart failure risk prediction in African Americans. HF-specific DNAm-based measures should be developed and evaluated for improvement in risk prediction.

Molecular Mechanisms of Intranasal Insulin in SAMP8 Mice

Research on intranasal delivery of drugs, peptides, and proteins has grown over the past decade as an alternate way to deliver substrates to the brain. Recent work has shown intranasal (INL) delivery of insulin improves memory and cognition in healthy subjects as well as patients with Alzheimer's disease (AD) and in AD mouse models. However, the molecular mechanism(s) for the beneficial effect of insulin on memory are still unclear. Using the SAMP8 mouse model of AD, we investigated the impact of INL insulin on protein and gene expression in brain regions including the olfactory bulb, hypothalamus, and hippocampus. We found genes and proteins in the insulin receptor signaling pathway were not activated by the doses tested. However, we did find the expression of genes present in the hippocampus involved in other pathways, especially those related to inflammation, were altered due to age and with a dose of INL insulin previously shown to improve cognition. These alternate pathways could be targets of insulin when delivered via the INL route to aid in memory improvement.

Retour d’expérience de deux structures d’urgences de centres hospitaliers généraux pendant la crise de la Covid-19

La Covid-19 s’est abattue sur l’Alsace en quelques jours, mettant à mal les hôpitaux de Mulhouse et de Colmar. Bien que proches, des différences notables existent au sein de ces deux structures en termes architecturaux et de ressources humaines. Comment cette vague a-t-elle modifié les organisations de chacun ? Quelles alternatives ont pu être mises en place ? Après la présentation de chaque site sont analysées les adaptations nécessaires afin d’absorber les flux de patients et leur proposer une prise en charge décente malgré des conditions parfois très dégradées. Nouvelles filières, modifications organisationnelles, renforts de personnel en interne puis en externe, augmentation capacitaire nette, recherches de solutions alternatives aux voies classiques d’approvisionnement des matériels… ont été une partie de la solution. Malgré les alertes du terrain, l’action nationale est restée en décalage de compréhension de la gravité de la situation locale, avec des recommandations et des actions soit inapplicables, soit trop tardives. Les établissements et professionnels de santé ont eu un sentiment d’isolement, renforcé par l’absence de représentant des tutelles et notamment de l’Agence régionale de santé sur le terrain. Deux éléments majeurs peuvent être mis en avant : une cohésion majeure de l’ensemble du centre hospitalier avec travail d’équipe et de terrain entre soignants et direction, et une implication de l’ensemble des acteurs de la médecine d’urgence (public, privé, libéraux, service départemental d’incendie et de secours) ; ils ont été les déterminants dans notre capacité à faire face à cet événement inédit.

A human ESC-based screen identifies a role for the translated lncRNA LINC00261 in pancreatic endocrine differentiation

Long noncoding RNAs (lncRNAs) are a heterogenous group of RNAs, which can encode small proteins. The extent to which developmentally regulated lncRNAs are translated and whether the produced microproteins are relevant for human development is unknown. Using a human embryonic stem cell (hESC)-based pancreatic differentiation system, we show that many lncRNAs in direct vicinity of lineage-determining transcription factors (TFs) are dynamically regulated, predominantly cytosolic, and highly translated. We genetically ablated ten such lncRNAs, most of them translated, and found that nine are dispensable for pancreatic endocrine cell development. However, deletion of LINC00261 diminishes insulin+ cells, in a manner independent of the nearby TF FOXA2. One-by-one disruption of each of LINC00261's open reading frames suggests that the RNA, rather than the produced microproteins, is required for endocrine development. Our work highlights extensive translation of lncRNAs during hESC pancreatic differentiation and provides a blueprint for dissection of their coding and noncoding roles.

Selective inhibition of peripheral cathepsin S reverses tactile allodynia following peripheral nerve injury in mouse

Cathepsin S (CatS) is a cysteine protease found in lysosomes of hematopoietic and microglial cells and in secreted form in the extracellular space. While CatS has been shown to contribute significantly to neuropathic pain, the precise mechanisms remain unclear. In this report, we describe JNJ-39641160, a novel non-covalent, potent, selective and orally-available CatS inhibitor that is peripherally restricted (non-CNS penetrant) and may represent an innovative class of immunosuppressive and analgesic compounds and tools useful toward investigating peripheral mechanisms of CatS in neuropathic pain. In C57BL/6 mice, JNJ-39641160 dose-dependently blocked the proteolysis of the invariant chain, and inhibited both T-cell activation and antibody production to a vaccine antigen. In the spared nerve injury (SNI) model of chronic neuropathic pain, in which T-cell activation has previously been demonstrated to be a prerequisite for the development of pain hypersensitivity, JNJ-39641160 fully reversed tactile allodynia in wild-type mice but was completely ineffective in the same model in CatS knockout mice (which exhibited a delayed onset in allodynia). By contrast, in the acute mild thermal injury (MTI) model, JNJ-39641160 only weakly attenuated allodynia at the highest dose tested. These findings support the hypothesis that blockade of peripheral CatS alone is sufficient to fully reverse allodynia following peripheral nerve injury and suggest that the mechanism of action likely involves interruption of T-cell activation and peripheral cytokine release. In addition, they provide important insights toward the development of selective CatS inhibitors for the treatment of neuropathic pain in humans.

Cross-reactive carbohydrate determinant interference in cellulose-based IgE allergy tests utilizing recombinant allergen components

Background

Cross-reactive carbohydrate determinant (CCD) structures found in plant and insect glycoproteins are commonly recognized by IgE antibodies as epitopes that can lead to extensive cross-reactivity and obscure in vitro diagnostic (IVD) serology results. With the introduction of component resolved diagnosis (CRD), recombinant non-glycosylated components have been utilized to mitigate the risk of CCD-specific IgE (sIgE) detection. However, a recent study has shown that CCD-sIgE may bind directly to the cellulose solid phase matrix used in certain in vitro diagnostic assays, eliminating the advantage of CRD over traditional extract-based testing. The aim of this study is to further investigate the prevalence of CCD-sIgE interference on a commonly-used in vitro sIgE automated platform which employs a cellulose-based matrix to immobilize CCD-free recombinant components.

Methods

Sera from patients sensitized to peanut, silver birch, and/or timothy grass were analyzed for CCD-sIgE reactivity on ImmunoCAP/Phadia and NOVEOS autoanalyzers against the MUXF3 carbohydrate component. Positive CCD-sIgE sera were further analyzed against non-glycosylated recombinant components bound to the ImmunoCAP solid phase in the absence and presence of a soluble CCD inhibitor. For comparison, sera were then analyzed on NOVEOS, a non-cellulose based automated sIgE assay.

Results

Sera from 35% of the sensitized population tested in this study were positive (≥0.35 kU/L) for CCD-sIgE. Of those positives, 17% resulted in CCD-sIgE-positive (false positive) results on ImmunoCAP using non-glycosylated allergosorbents that were negative on NOVEOS. Sera producing false-positive results on ImmunoCAP had varying levels of CCD-sIgE from 0.67 kU/L to 36.52 kU/L. The incidence of CCD interference was predominantly delimited to low-positive IgE results (0.35 kU_A/L– 3.00 kU_A/L).

Conclusion

Falsely elevated diagnostic allergen-sIgE results can commonly occur due to the presence of CCD-sIgE using assays that employ a carbohydrate matrix-based allergosorbent. Even the use of non-glycosylated recombinant allergenic components coupled to cellulose matrices do not reduce their risk of detection. The risk of CCD interference that compromises quantitative IgE results can be mitigated by the addition of a soluble CCD inhibitor to positive CCD-sIgE containing sera or by alternatively using a non-cellulose based sIgE assay, such as the NOVEOS assay.

Association of Mineral Bone Disorder With Decline in Residual Kidney Function in Incident Hemodialysis Patients

Abnormalities of mineral bone disorder (MBD) parameters have been suggested to be associated with poor renal outcome in predialysis patients. However, the impact of those parameters on decline in residual kidney function (RKF) is uncertain among incident hemodialysis (HD) patients. We performed a retrospective cohort study in 13,772 patients who initiated conventional HD during 2007 to 2011 and survived 6 months of dialysis. We examined the association of baseline serum phosphorus, calcium, intact parathyroid hormone (PTH), and alkaline phosphatase (ALP) with a decline in RKF. Decline in RKF was assessed by estimated slope of renal urea clearance (KRU) over 6 months from HD initiation. Our cohort had a mean ± SD age of 62 ± 15 years; 64% were men, 57% were white, 65% had diabetes, and 51% had hypertension. The median (interquartile range [IQR]) baseline KRU level was 3.4 (2.0, 5.2) mL/min/1.73 m² . The median (IQR) estimated 6-month KRU slope was -1.47 (-2.24, -0.63) mL/min/1.73 m² per 6 months. In linear regression models, higher phosphorus categories were associated with a steeper 6-month KRU slope compared with the reference category (phosphorus 4.0 to <4.5 mg/dL). Lower calcium and higher intact PTH and ALP categories were also associated with a steeper 6-month KRU slope compared with their respective reference groups (calcium 9.2 to <9.5 mg/dL; intact PTH 150 to <250 pg/mL; ALP <60 U/L). The increased number of parameter abnormalities had an additive effect on decline in RKF. Abnormalities of MBD parameters including higher phosphorus, intact PTH, ALP and lower calcium levels were independently associated with decline in RKF in incident HD patients. © 2019 American Society for Bone and Mineral Research. © 2019 American Society for Bone and Mineral Research.

Letrozole and palbociclib versus chemotherapy as neoadjuvant therapy of high-risk luminal breast cancer

Background

Palbociclib is a CDK4/6 inhibitor with demonstrated efficacy and safety in combination with endocrine therapy in advanced luminal breast cancer (LBC). We evaluated the respective efficacy and safety of chemotherapy and letrozole-palbociclib (LETPAL) combination as neoadjuvant treatment in patients with high-risk LBC.

Patients and methods

NeoPAL (UCBG10/4, NCT02400567) is a randomised, parallel, non-comparative phase II study. Patients with ER-positive, HER2-negative, Prosigna®-defined luminal B, or luminal A and node-positive, stage II-III breast cancer, not candidate for breast-conserving surgery, were randomly assigned to either letrozole (2.5 mg daily) and palbociclib (125 mg daily, 3 weeks/4) during 19 weeks, or to FEC100 (5FU 500 mg/m2, epirubicin 100 mg/m2, cyclophosphamide 500 mg/m2)×3 21-day courses followed by docetaxel 100 mg/m2×3 21-day courses. Primary end point was residual cancer burden (RCB 0-I rate). Secondary end points included clinical response, proliferation-based markers, and safety.

Results

Overall, 106 patients were randomised [median Prosigna® ROR Score 71 (22-93)]. RCB 0-I was observed in four and eight patients in LETPAL [7.7% (95% CI 0.4-14.9)] and chemotherapy [15.7% (95% CI 5.7-25.7)] arms, respectively. Pathological complete response rates were 3.8% and 5.9%. Clinical response (75%) and breast-conserving surgery rates (69%) were similar in both arms. Preoperative Endocrine Prognostic Index 0 scores (breast cancer-specific survival) were observed in 17.6% and 8.0% of patients in LETPAL and chemotherapy arms, respectively. Safety profile was as expected, with 2 versus 17 serious adverse events (including 11 grade 4 serious AEs in the chemotherapy arm).

Conclusion

LETPAL combination was associated with poor pathological response but encouraging clinical and biomarker responses in Prosigna®-defined high-risk LBC. Contemporary chemotherapy regimen was associated with poor pathological and biomarker responses, with a much less favourable safety profile. LETPAL combination might represent an alternative to chemotherapy in early high-risk LBC.

Clinical Trial Number

NCT02400567.

Cutaneous Branch of the Obturator Nerve Extending to the Medial Ankle and Foot: A Report of Two Cadaveric Cases

The area of skin supplied by the cutaneous branch of the obturator nerve (CBO) is highly variable. Although most introductory anatomy texts describe the CBO as innervating only a portion of the medial thigh, there are numerous reports in the literature of CBOs passing the knee to innervate the proximal, middle, or even distal leg. There are no previous reports of CBOs extending to the ankle and foot. Herein we describe 2 cases of CBOs extending at least to the medial foot. Both cases were discovered incidentally, during routine cadaver dissections by osteopathic and podiatric medical students in the anatomy laboratory of Western University of Health Sciences in California. In both instances, the anomalously long CBOs shared several characteristics: (1) they arose as direct branches of the anterior division of the obturator nerve, not from the subsartorial plexus; (2) they coursed immediately posterior to the great saphenous vein from the distal thigh to the distal leg, only deviating away from the saphenous vein just above the medial malleolus; and (3) they terminated in radiating fibers to the posterior half of the medial ankle and foot. In both cases, the saphenous branch of the femoral nerve was present but restricted to the area anterior to the great saphenous vein. It is likely that the variant CBOs carried fibers of the L4 spinal nerve and thus provided cutaneous innervation to the medial foot and ankle, a function most commonly reserved for the saphenous branch of the femoral nerve distal to the knee. Saphenous neuropathy is a common postoperative complication of saphenous cutdowns for coronary artery bypass grafts, so the potential involvement of a long CBO can add additional complexity to regional anesthetic blocks for foot and ankle surgery and procedures such as vein harvesting for coronary artery bypass grafts.

Association between hydroxychloroquine levels and disease activity in a predominantly Hispanic systemic lupus erythematosus cohort

OBJECTIVES

Hydroxychloroquine (HCQ) is a key therapy in systemic lupus erythematosus (SLE). Medication non-adherence is reported in up to 80% of lupus patients and results in increased morbidity, mortality, and health care utilization. HCQ levels are a sensitive and reliable method to assess medication adherence. Our study evaluated the role of HCQ level measurement in routine clinical care and its association with disease activity in a predominantly Hispanic population.

METHODS

SLE patients from the Columbia University Lupus cohort treated with HCQ for ≥ 6 months and reporting medication adherence were included. HCQ levels were measured by whole blood high performance liquid chromatography. Non-adherence was defined as an HCQ level <500 ng/ml. The association between HCQ levels and disease activity measured by Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) was evaluated.

RESULTS

One hundred and eight patients were enrolled; the median age was 38 years, 91% were female, and 63% were Hispanic. The median SLEDAI-2K was 4.3 (0-20). Forty-one percent of patients had an HCQ level <500 ng/ml consistent with non-adherence, of which 19% had undetectable levels. A higher SLEDAI-2K score was associated with low HCQ levels (p = 0.003). This association remained significant after adjusting for depression (p = 0.0007).

CONCLUSION

HCQ levels < 500 ng/ml were associated with higher disease activity and accounted for 32% of the SLEDAI-2K variability. HCQ blood measurement is a simple and reliable method to evaluate medication adherence in SLE. Reasons for non-adherence (levels < 500 ng/ml) should be further explored and addressed.