Substrate oxidation during exercise in childhood acute lymphoblastic leukemia survivors

Children with acute lymphoblastic leukemia (ALL) are at high risk of developing long-term cardiometabolic complications during their survivorship. Maximal fat oxidation (MFO) is a marker during exercise of cardiometabolic health, and is associated with metabolic risk factors. Our aim was to characterize the carbohydrate and fat oxidation during exercise in childhood ALL survivors. Indirect calorimetry was measured in 250 childhood ALL survivors to quantify substrate oxidation rates during a cardiopulmonary exercise test. A best-fit third-order polynomial curve was computed for fat oxidation rate (mg/min) against exercise intensity (%V ̇ O2peak) and was used to determine the MFO and the peak fat oxidation (Fatmax). The crossover point was also identified. Differences between prognostic risk groups were assessed (ie, standard risk [SR], high risk with and without cardio-protective agent dexrazoxane [HR + DEX and HR]). MFO, Fatmax and crossover point were not different between the groups (p = .078; p = .765; p = .726). Fatmax and crossover point were achieved at low exercise intensities. A higher MFO was achieved by men in the SR group (287.8 ± 111.2 mg/min) compared to those in HR + DEX (239.8 ± 97.0 mg/min) and HR groups (229.3 ± 98.9 mg/min) (p = .04). Childhood ALL survivors have low fat oxidation during exercise and oxidize carbohydrates at low exercise intensities, independently of the cumulative doses of doxorubicin they received. These findings alert clinicians on the long-term impact of cancer treatments on childhood ALL survivors' substrate oxidation.

Abnormal HDL lipid and protein composition following pediatric cancer treatment: an associative study

BACKGROUND

Long-term childhood cancer survivors (CCS) are at high risk of having dyslipidemia including low high density lipoprotein cholesterol (HDL-C). However, little is known about the prevalence of low HDL-C and the impact of therapy exposure on HDL composition early after treatment is terminated.

METHODS

This associative study included 50 children and adolescents who had completed their cancer treatments (< 4 years). Clinical characteristics (demographic, diagnosis, treatment, anthropometric parameters), fasting plasma lipids, apoliporoteins (Apo) A-I and composition of HDL fractions (HDL2 and HDL3) were assessed. Data were stratified according to the presence of dyslipidemia and median doses of therapeutic agents and compared using Fisher exact or Mann-Whitney tests. Univariate binary logistic regression analyses were carried out to evaluate the associations between the clinical and biochemical characteristics and having low HDL-C. Composition of HDL2 and HDL3 particles was assessed in a sub-group of 15 patients and compared to 15 age- and sex-matched healthy controls using Wilcoxon paired test.

RESULTS

Of the 50 pediatric cancer patients included in this study (mean age: 11.30 ± 0.72 y; mean time since end of treatment: 1.47 ± 0.12 y; male: 38%), 8 had low HDL-C (16%), all of which were adolescent at diagnosis. Higher doses of doxorubicin were associated with lower HDL-C and Apo A-I levels. In hypertriglyceridemic patients and compared to normolipidemics, triglycerides (TG) content was greater in HDL2 and HDL3 fractions whereas esterified cholesterol (EC) content was lower in HDL2. Enrich TG content of HDL3 and lower EC of HDL2 was found in patients exposed to ≥ 90 mg/m² doxorubicin. Factors positively associated with the risk of having low HDL-C were age, being overweight or obese and exposure to doxorubicin ≥ 90 mg/m². Compared to healthy controls, a sub-group of 15 patients showed higher TG and free cholesterol (FC) content of HDL2 and HDL3 and lower EC content in HDL3.

CONCLUSIONS

Overall, we found abnormalities in HDL-C and Apo A-I levels and in HDL composition early after pediatric cancer treatment that are influenced by age, overweight or obesity status and exposure to doxorubicin.

Needs, Barriers and Facilitators of Adolescents Participating in a Lifestyle Promotion Program in Oncology: Stakeholders, Adolescents and Parents’ Perspective

Treatments for adolescent cancer can cause debilitating side effects in the short- and long-term such as nausea and malnutrition but also cardiometabolic disturbances. Although the risk for cardiometabolic complications is greater for adolescents with cancer than younger ones, adolescents typically respond poorly to family-oriented health promotion programs. This study aims to assess the needs, barriers and facilitators to healthy lifestyle promotion interventions for adolescents with cancer and how to best adapt these interventions for them. Interviews were held with adolescents treated for cancer (n = 9) and parents (n = 6), focus groups were conducted with stakeholders working in oncology (n = 12) and self-report questionnaires were sent to stakeholders involved in a health promotion intervention (n = 6). At the time of interview, mean age of adolescent participants (40% female) was 17.0 ± 1.9 years (mean age at diagnosis: 14.6 ± 1.6 years). Verbatim and responses to questionnaires were coded and analyzed using qualitative methods. Stakeholder stated that adolescents with cancer need to access activities adapted to their age, to communicate with peers going through a similar experience, and to preserve their schooling and friendships. Barriers to intervention reported by adolescents, parents and stakeholders include lack of motivation, schedule conflicts, fatigue and treatment side effects. Some of the barriers mentioned by adolescents and parents include pain, post-surgery problems, school, physical deconditioning, and lack of time. Facilitators mentioned by adolescents and parents comprise trust in stakeholders’ expertise, personalized approaches, scheduling flexibility. Stakeholders recommended to build trust in the relationship, favoring non-moralizing teachings, adapt interventions to adolescents’ limited attention span and avoiding the use of long-term health benefits as a motivator.

Abstract 2003: Poor diet quality is associated with immune aging in survivors of pediatric acute lymphoblastic leukemia

Rationale and objectives: Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer. Despite a 90% five-year survival rate, survivors of childhood ALL often suffer from late effects, including cardiometabolic disorders. Contributing factors such as inflammation and oxidative stress, combined with drug treatments, can induce premature aging and cellular senescence with a significant impact on cardiometabolic disorders. Premature aging can lead to decreased thymic T-cell production, resulting in decreased circulation of T-cell receptor excision circles (TRECs). Because diet has been associated with cardiometabolic disorders, we hypothesized that the quality of diet in children who had survived ALL was related to the immune aging biomarker TREC, in concert with inflammatory status.

Methods: Adolescent and young adult survivors of pediatric ALL of the PETALE cohort (n=241, 22.1 ± 6.3 years at diagnosis, 49.4% male) were examined in their profile for TREC levels (by qPCR) and for adherence to 6 diet quality indices.

Results: Adjusted linear regressions revealed that the Healthy Diet Indicator (HDI) was associated with TREC levels (β=50.0, p=0.005, adjusted p=0.03). After performing a conceptual relational analysis (CAR) for data mining of various biomarkers of inflammation, oxidative stress, endotoxemia, and endothelial or adipose dysfunction; interleukin-6 (IL-6) and C-reactive protein (CRP) were found to be negatively associated with TREC levels (β= -80 and -80.1, p=0.017 and 0.026, respectively) but not with HDI. Further analysis revealed that IL-6 and CRP levels were moderators, but not mediators, of the association between HDI and TREC.

Conclusion: This study supports the positive impact of a healthy diet on premature immune aging and the moderating role of inflammation in this association.

Citation Format: Abderrahim Benmoussa, Tibila Kientega, Sophia Morel, Guillaume Cardin, Sophie Bérard, Mickael wajnberg, Petko Valtchev, Alexandre Blondin-Masse, Daniel Curnier, Maja Krajinovic, Caroline Laverdière, Daniel Sinnett, Emile Levy, Sophie Marcoux, Francis Rodier, Valérie Marcil. Poor diet quality is associated with immune aging in survivors of pediatric acute lymphoblastic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2003.

Aneurysmal cyclic circumferential stretch affects the expression of endothelial genes involved in vascular homeostasis

Funding Acknowledgements

Type of funding sources: None.

Background

Intracranial aneurysm (IA) rupture is a common cause of hemorrhagic stroke. IAs are present in 3 to 5% of the general population and the annual rupture rate of an IA has been estimated to 1%. Once formed, an IA can rupture immediately, grow before rupturing, or remain stable. Predicting the evolution of an unruptured IA is very difficult. Indeed, the biology of the IA wall is complex and the precise biomechanical processes leading to aneurysm wall rupture are not yet known. While the contribution of wall shear stress in IA disease has been demonstrated in several studies, the role of cyclic circumferential stretch (CCS) remains poorly understood.

Purpose

The levels of CCS in saccular IAs are unknown but are generally considered very low or even absent. The goal of our study was to investigate the transcriptional response of endothelial cells (ECs) to absence of CCS and the potential impact on the endothelium function.

Methods

Human umbilical veins ECs (HUVECs) from 6 different donors were exposed to physiological CCS levels for cerebral arteries (6% stretch) or to aneurysmal CCS (0%) for 48h using the Flexcell strain unit FX-5000T, and unbiased transcriptomics were performed. The expression of selected genes was confirmed by qPCR.

Results

As a validation of our methodology, we verified the induction of eNOS phosphorylation after exposure of the ECs to physiological CCS. Stretched EC samples display a high similarity between each other while EC samples under aneurysmal CCS were spread-out on a multidimensional scaling plot. The differential gene expression of ECs exposed to aneurysmal or physiological CCS revealed 51 up-regulated genes and 49 down-regulated genes in absence of CCS. The gene set enrichment analysis identified 70 up-regulated and 38 down-regulated pathways in HUVECs exposed to aneurysmal CCS. Up-regulated pathways were involved in oxidative stress, angiogenic and inflammatory pathways, and the down-regulated pathways in proliferation and extracellular matrix-receptor interactions. We confirmed by qPCR the down-regulation by aneurysmal CCS of Gja4 and Gja5, genes coding for the gap junction proteins Connexin37 (Cx37) and Connexin40 (Cx40), respectively. Connexins (Cxs) are crucial proteins for endothelial homeostasis, vascular function, endothelial cell cycle regulation and inflammation, and their role in the context of IA disease will be further studied.

Conclusion

Our results indicate that physiological CCS prevents large deviation in ECs and regulate the expression of genes essential for maintaining vascular homeostasis. The down-regulation of endothelial Cx37 and Cx40 under aneurysmal CSS may contribute to the endothelial dysfunction associated with IA progression. Further investigation may help to better define the role of Cxs in aneurysmal disease and to understand the significance of absence of CCS in IA disease progression.

Changes in endothelial characteristics as a new strategy to identify intracranial aneurysm at risk of rupture

Funding Acknowledgements

Type of funding sources: None.

Background

Intracranial aneurysm (IA) is an arterial disease resulting in abnormal enlargement of the vessel lumen. Most IAs are asymptomatic but their rupture induces subarachnoid hemorrhage with 24% resulting in death and 11% in severe disability. Occlusion of an unruptured IA by microsurgical or endovascular treatment results in a procedural morbidity and mortality of between 4 to 7%. Decision making between "intervention" or "continuing observation" for an individual patient is currently based on clinical scores and further supported by radiologic imaging of IA characteristics including the observation of vessel wall enhancement (VWE) on magnetic resonance imaging (MRI). VWE reflects a local accumulation of colloid contrast agent, which has been associated with IA wall instability. The pathophysiology of VWE is unknown but enhanced permeability of arterial endothelium, excessive macrophage infiltration, or presence of vasa vasorum have been proposed as potential mechanisms.

Purpose

The goal of our study is to investigate the expression of tight junction (TJ) proteins in the arterial endothelium of human IA domes in the context of IA wall instability. To this end, we have compared ruptured and unruptured IA domes from a human IA biobank.

Methods

Human aneurysms from the middle cerebral artery were obtained during microsurgery by resection of the IA dome after clipping of the neck, embedded in paraffin, and then sectioned and stained for the endothelial cell marker CD31 and the TJ proteins Claudin-5 and Zonula occludens-1 (ZO-1). The expression of these proteins was compared between ruptured and unruptured IAs. Results are expressed as a median (interquartile range).

Results

Histological analyses for CD31 revealed that endothelial cell coverage in ruptured (N=16) IAs tended to be decreased compared to unruptured (N=30) domes (27% (10-49) versus 38% (23-77) respectively, P=0.06). Interestingly, in ruptured aneurysms the expression of the TJ proteins Claudin-5 (1.70um (1.52-2.04)) and ZO-1 (2.29um (1.96-2.75) was lower in comparison with unruptured samples (Claudin-5: 2.15um (1.90-2.76), P&lt;0.05; ZO-1: 2.66um (2.40-3.66), P&lt;0.05).

Conclusion

Our study revealed reduced expression of Claudin-5 and ZO-1 in ruptured IAs in comparison with unruptured IA domes. Reduction in TJ proteins may lead to increased endothelial permeability thus favoring the accumulation of MRI contrast agent in the IA wall and the observation of VWE. Focusing on changes in endothelial characteristics and permeability may represent a new strategy to identify IAs at risk of rupture.

Pannexin1 as a new target for prevention of cardiac ischemia/reperfusion injury

Funding Acknowledgements

Type of funding sources: None.

Background

Ischemic heart disease is the main cause of mortality worldwide. Ischemia occurs when blood flow to the myocardium is severely restricted. Reperfusion is crucial to avoid irreversible cell damage, which may lead to heart failure. No effective therapy is available in clinics to protect the heart from ischemia/reperfusion (I/R) injury. An inappropriate inflammatory response may worsen I/R injury. Thus, endothelial cells (ECs) are activated in response to I/R, which may drive an inflammatory response by releasing ATP through Pannexin1 (Panx1) channels. ATP acts further as a ‘find me’ signal for leukocytes. It is known that Panx1 channels open in response to oxygen and glucose deprivation –hallmarks of ischemia.

Purpose

We investigated the potential role of Panx1 in cardiac I/R injury.

Methods

Panx1 expression and function was detected by immunofluorescence, Western blot and ATP release assays. Cardiac function was measured in Langendorff-perfused hearts from WT or Panx1-/- mice and ex vivo subjected to 30min no-flow ischemia followed by 60min reperfusion with/without ischemic pre-conditioning (IPC; 3x5min). We induced in vivo I/R (30min/24h) by ligating the left coronary artery in WT, Panx1-/- mice, mice with Ly6G-Cre-mediated deletion of Panx1 and Panx1fl/fl controls. Infarct size, neutrophil recruitment and Troponin-I release were measured.

Results

Panx1 expression was detected in coronary and microvascular ECs, neutrophils and cardiomyocytes. After in vivo I/R, serum Troponin-I and infarct size were less pronounced in Panx1-/- mice, but neutrophil infiltration into the infarcted area was similar between Panx1-/- and WT mice. Serum Troponin-I and infarct size were not different between mice with neutrophil-specific deletion of Panx1 and Panx1fl/fl mice, suggesting that cardioprotection by Panx1 deletion rather involved cardiomyocytes than the inflammatory response. Physiological cardiac function in WT and Panx1-/- hearts was similar. However, Panx1-/- hearts showed enhanced left ventricle developed pressure and better recovery of cardiac contractility (dP/dtmax) and cardiac relaxation (dP/dtmin) after I/R. Both the time to onset of contracture (TTOC) and time to maximal contracture (TTMC) were delayed in Panx1-/- hearts. This improved cardiac recovery was abolished in Panx1-/- hearts subjected to IPC prior to I/R. Similarly, TTOC and TTMC did not vary between WT and Panx1-/- mice following IPC, suggesting altered mitochondrial function in Panx1-/- cardiomyocytes. Finally, Panx1 was found in mitochondria and mitochondrial ATP content was increased in Panx1-/- cardiomyocytes.

Conclusion

Panx1-/- mice display decreased sensitivity to cardiac I/R injury, resulting in smaller infarcts and increased recovery of left ventricular function. This cardioprotective effect of Panx1 deletion seems to involve cardiac mitochondria rather than a reduced inflammatory response. Thus, Panx1 may represent a new target for controlling cardiac reperfusion damage.

Intestinal Dysbiosis and Development of Cardiometabolic Disorders in Childhood Cancer Survivors: A Critical Review

Significance: Survivors of pediatric cancers have a high risk of developing side effects after the end of their treatments. Many potential factors have been associated with the onset of cardiometabolic disorders (CMD), including cancer disease itself, chemotherapy, hormonal treatment, radiotherapy, and genetics. However, the precise etiology and underlying mechanisms of these long-term complications are poorly understood. Recent Advances: Greater awareness is currently paid to the role of microbiota in the emergence of cancers and modulation of cancer therapies in both children and adults. Alterations in the composition and diversity of intestinal microbiota can clearly influence tumor development and progression as well as immune responses and clinical output. As dysbiosis is closely linked to the development of host metabolic diseases, including obesity, metabolic syndrome, type 2 diabetes, and non-alcoholic fatty liver disease, it may increase the risk of CMD in cancer populations. Critical Issues: Only limited studies targeting the profile of intestinal dysbiosis before and after cancer treatment have been conducted. Further, the exact contribution of intestinal dysbiosis to the development of CMD in cancer survivors is poorly appreciated. This review intends to clarify the influence of gut microbiota on CMD in childhood cancer survivors, elucidate the potential mechanisms, and evaluate the latest research on the interplay between diet/food supplement, microbiota, and cancer-related CMD. Future Directions: The implication of intestinal dysbiosis in late metabolic complications of childhood cancer survivors should be clarified. Intervention strategies could be developed to reduce the risk of survivors to CMD. Antioxid. Redox Signal. 34, 223-251.

Diet Quality Is Associated with Cardiometabolic Outcomes in Survivors of Childhood Leukemia

There is little information about how diet influences the health of childhood acute lymphoblastic leukemia (cALL) survivors. This study explores the associations between diet quality indices, cardiometabolic health indicators and inflammatory biomarkers among cALL survivors. Participants were part of the PETALE study (n = 241, median age: 21.7 years). Adherence to 6 dietary scores and caloric intake from ultra-processed foods were calculated. Multivariate logistirac regressions, Student t-tests and Mann-Whitney tests were performed. We found that 88% of adults and 46% of children adhered poorly to the Mediterranean diet, 36.9% had poor adherence to the World Health Organisation (WHO) recommendations and 76.3% had a diet to be improved according to the HEI-2015 score. On average, ultra-processed foods accounted for 51% of total energy intake. Low HDL-C was associated with a more inflammatory diet (E-DIITM score) and higher intake of ultra-processed foods. A greater E-DII score was associated with elevated insulin resistance (HOMA-IR), and consumption of ultra-processed foods was correlated with high triglycerides. Circulating levels of TNF-α, adiponectin and IL-6 were influenced by diet quality indices, while CRP and leptin were not. In conclusion, survivors of cALL have poor adherence to dietary recommendations, adversely affecting their cardiometabolic health.

How PrEP users constitute a community in the MSM population through their specific experience and management of stigmatization. The example of the French ANRS-PREVENIR study

The ANRS-PREVENIR (2017-2020) prospective cohort study aims to reduce the number of new HIV infections in the "Ile-de-France" region in France, by enrolling individuals at high risk of HIV infection and proposing daily and on-demand pre-exposure prophylaxis (PrEP). The qualitative component of the ANRS-PREVENIR study aimed to investigate social and relational evolutions associated with PrEP use in men who have sex with men (MSM). In 2018, 12 focus groups with MSM (n = 68) were conducted by a social sciences researcher in Paris. A thematic analysis was performed. Results showed that stigma concerning PrEP use is a complex issue, with various kinds of stigmatization being practiced, sometimes even by the wider MSM population and PrEP users themselves. All types of stigma identified were expressed in forms of verbal abuse which made PrEP use taboo. Inside the wider MSM population a PrEP-user "community" was identified which shared a certain complicity in terms of values and a positive attitude towards PrEP. The emergence of new intragroup and intergroup social norms should be taken into account by policy makers to promote a more positive image of PrEP users.

Dietary Intakes Are Associated with HDL-Cholesterol in Survivors of Childhood Acute Lymphoblastic Leukaemia

Survivors of childhood acute lymphoblastic leukemia (cALL) are at high risk of developing dyslipidemia, including low HDL-cholesterol (HDL-C). This study aimed to examine the associations between food/nutrient intake and the levels of HDL-C in a cohort of children and young adult survivors of cALL. Eligible participants (n = 241) were survivors of cALL (49.4% boys; median age: 21.7 years old) recruited as part of the PETALE study. Nutritional data were collected using a validated food frequency questionnaire. Fasting blood was used to determine participants' lipid profile. Multivariable logistic regression models were fitted to evaluate the associations between intakes of macro- and micronutrients and food groups and plasma lipids. We found that 41.3% of cALL survivors had at least one abnormal lipid value. Specifically, 12.2% had high triglycerides, 17.4% high LDL-cholesterol, and 23.1% low HDL-C. Low HDL-C was inversely associated with high intake (third vs. first tertile) of several nutrients: proteins (OR: 0.27, 95% CI: 0.08-0.92), zinc (OR: 0.26, 95% CI: 0.08-0.84), copper (OR: 0.34, 95% CI: 0.12-0.99), selenium (OR: 0.17, 95% CI: 0.05-0.59), niacin (OR: 0.25, 95% CI: 0.08-0.84), riboflavin (OR: 0.31, 95% CI: 0.12-0.76) and vitamin B12 (OR: 0.35, 95% CI: 0.13-0.90). High meat consumption was also inversely associated (OR: 0.28, 95% CI: 0.09-0.83) with low HDL-C while fast food was positively associated (OR: 2.41, 95% CI: 1.03-5.63) with low HDL-C. The role of nutrition in the development of dyslipidemia after cancer treatment needs further investigation.

A Bayesian multivariate latent t-regression model for assessing the association between corticosteroid and cranial radiation exposures and cardiometabolic complications in survivors of childhood acute lymphoblastic leukemia: a PETALE study

Background

Childhood acute lymphoblastic leukemia (cALL) is the most frequent pediatric cancer. Over the past decades, treatment of cALL has significantly improved, with cure rates close to 90%. However intensive chemotherapy and cranial radiotherapy (CRT) during a critical period of a child’s development have been shown to lead to significant long-term side effects including cardiometabolic complications. Using the PETALE (Prévenir les effets tardifs des traitements de la leucémie aiguë lymphoblastique chez l’enfant) cALL survivor cohort, we investigated the association between combined cumulative corticosteroids (CS) doses and CRT exposures and obesity, insulin resistance, (pre-)hypertension, and dyslipidemia jointly.

Methods

A Bayesian multivariate latent-t model which accounted for our correlated binary outcomes was used for the analyses (n = 241 survivors). CS doses were categorized as low (LD) or high (HD). Combined exposure levels investigated were: 1) LD/no CRT; 2) LD/CRT, and; 3) HD/CRT. We also performed complementary sensitivity analyses for covariate adjustment.

Results

Prevalence of cardiometabolic complications ranged from 12.0% for (pre-)hypertension to 40.2% for dyslipidemia. The fully adjusted odds ratio (OR) for dyslipidemia associated with LD/CRT (vs. LD/No CRT) was OR = 1.98 (95% credible interval (CrI): 1.02 to 3.88). LD/CRT level also led to a 0.15 (95% CrI: 0.00 to 0.29) excess risk to develop at least one cardiometabolic complication. Except for obesity, adjusted results for the highest exposure category HD/CRT were generally similar to those for LD/CRT albeit not statistically significant. White blood cell count at diagnosis, a proxy for cALL burden at diagnosis, was found associated with insulin resistance (OR = 1.08 for a 10-unit increase (× 10⁹/L), 95% CrI: 1.02 to 1.14).

Conclusions

Our results indicated that combined LD/CRT exposure is a likely determinant of dyslipidemia among cALL survivors. No evidence was found to suggest that high doses of CS lead to additional risk for obesity, insulin resistance, (pre-)hypertension, and dyslipidemia beyond that induced by CRT. The multivariate model selected for analyses was judged globally useful to assess potential exposure-related concomitance of binary outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12874-019-0725-9) contains supplementary material, which is available to authorized users.

Insight from mitochondrial functions and proteomics to understand cardiometabolic disorders in survivors of acute lymphoblastic leukemia

BACKGROUND

Childhood acute lymphoblastic leukemia (cALL) is the most prevalent form of cancer in children. Due to advances in treatment and therapy, young cALL subjects now achieve a 90% survival rate. However, this tremendous advance does not come without consequence since ~2/3 of cALL survivors are affected by long-term and late, severe complications. Although the metabolic syndrome is a very serious sequel of cALL, the mechanisms remain undefined. It is also surprising to note that the mitochondrion, a central organelle in metabolic functions and the main cellular energy generator, have not yet been explored.

OBJECTIVES

To determine whether cALL survivors exhibit impairments in their mitochondrial functions and proteomic profiling in relationship with metabolic disorders in cALL survivors compared to healthy controls.

METHODS AND RESULTS

Anthropometric measures, metabolic characteristics and lipid profiles were assessed, mitochondria isolated from peripheral blood mononuclear cells, and proteomic analyzed. Our data demonstrated that metabolically. Unhealthy survivors exhibited several metabolic syndrome components (e.g. overweight, insulin resistance, dyslipidemia, inflammation) whereas Healthy cALL survivors resemble the Controls. In line with these abnormalities, functional experiments in these subjects revealed a significant decrease in the protein expression of mitochondrial antioxidant superoxide dismutase, PGC1-α transcription factor (a key modulator of mitochondrion biogenesis), and an increase in pro-apoptotic cytochrome c. Proteomic analysis of mitochondria by mass spectrometry revealed changes in the regulation of proteins related to inflammation, apoptosis, energy production, redox and antioxidant activity, fatty acid β-oxidation, protein transport and metabolism, and signalling pathways between groups.

CONCLUSIONS

Through the use of proteomic analysis, our work demonstrated a number of significant alterations in protein expression in mitochondria of cALL survivors, especially the metabolically Unhealthy survivor group. Further investigation of these proteins may help delineate the mechanisms by which mitochondrial dysfunctions exert cardiometabolic derangements in cALL survivors.

Development and relative validation of a food frequency questionnaire for French-Canadian adolescent and young adult survivors of acute lymphoblastic leukemia

BACKGROUND

Survivors of childhood acute lymphoblastic leukemia (cALL) experience cardiometabolic and bone complications after treatments. This study aimed at developing and validating an interview-administrated food frequency questionnaire (FFQ) that will serve to estimate the impact of nutrition in the development of long-term sequalea of French-Canadian cALL survivors.

METHODS

The FFQ was developed to assess habitual diet, Mediterranean diet score, nutrients promoting bone health and antioxidants. It was validated using a 3-day food record (3-DFR) in 80 cALL survivors (50% male) aged between 11.4 and 40.1 years (median of 18.0 years). Reproducibility was evaluated by comparing FFQs from visit 1 and 2 in 29 cALL survivors.

RESULTS

When compared to 3-DFR, the mean values for macro- and micronutrient intake were overestimated by our FFQ with the exception of lipid-related nutrients. Correlations between nutrient intakes derived from the FFQs and the 3-DFRs showed moderate to very good correlations (0.46-0.74). Intraclass correlation coefficients assessing FFQ reproducibility ranged from 0.62 to 0.92, indicating moderate to good reliability. Furthermore, classification into quartiles showed more than 75% of macro- and micronutrients derived from FFQs 1 and 2 classified into the same or adjacent quartile.

CONCLUSIONS

Overall, our results support the reproducibility and accuracy of the developed FFQ to appropriately classify individuals according to their dietary intake. This validated tool will be valuable for future studies analyzing the impact of nutrition on cardiometabolic and bone complications in French-speaking populations.

Cardiometabolic Risk Factors in Childhood, Adolescent and Young Adult Survivors of Acute Lymphoblastic Leukemia - A Petale Cohort

Our objectives were to assess the prevalence of cardiometabolic complications in children, adolescents, and young adult survivors of childhood acute lymphoblastic leukemia (cALL), to identify their predictors and the risk compared to the Canadian population. We performed a cardiometabolic assessment of cALL survivors from the PETALE cohort (n = 247, median age at visit of 21.7 years). In our group, overweight and obesity affected over 70% of women. Pre-hypertension and hypertension were mostly common in men, both adults (20%) and children (19%). Prediabetes was mainly present in women (6.1% of female adult survivors) and 41.3% had dyslipidemia. Cranial radiation therapy was a predictor of dyslipidemia (RR: 1.60, 95% CI: 1.07–2.41) and high LDL-cholesterol (RR: 4.78, 95% CI: 1.72–13.28). Male gender was a predictor for pre-hypertension and hypertension (RR: 5.12, 95% CI: 1.81–14.46). Obesity at the end of treatment was a predictor of obesity at interview (RR: 2.07, 95% CI: 1.37–3.14) and of metabolic syndrome (RR: 3.04, 95% CI: 1.14–8.09). Compared to the general population, cALL survivors were at higher risk of having the metabolic syndrome, dyslipidemia, pre-hypertension/hypertension and high LDL-cholesterol, while the risk for obesity was not different. Our results support the need for early screening and lifestyle intervention in this population.

Lipid and lipoprotein abnormalities in acute lymphoblastic leukemia survivors

Survivors of acute lymphoblastic leukemia (ALL), the most common cancer in children, are at increased risk of developing late cardiometabolic conditions. However, the mechanisms are not fully understood. This study aimed to characterize the plasma lipid profile, Apo distribution, and lipoprotein composition of 80 childhood ALL survivors compared with 22 healthy controls. Our results show that, despite their young age, 50% of the ALL survivors displayed dyslipidemia, characterized by increased plasma triglyceride (TG) and LDL-cholesterol, as well as decreased HDL-cholesterol. ALL survivors exhibited lower plasma Apo A-I and higher Apo B-100 and C-II levels, along with elevated Apo C-II/C-III and B-100/A-I ratios. VLDL fractions of dyslipidemic ALL survivors contained more TG, free cholesterol, and phospholipid moieties, but less protein. Differences in Apo content were found between ALL survivors and controls for all lipoprotein fractions except HDL₃ HDL₂, especially, showed reduced Apo A-I and raised Apo A-II, leading to a depressed Apo A-I/A-II ratio. Analysis of VLDL-Apo Cs disclosed a trend for higher Apo C-III₁ content in dyslipidemic ALL survivors. In conclusion, this thorough investigation demonstrates a high prevalence of dyslipidemia in ALL survivors, while highlighting significant abnormalities in their plasma lipid profile and lipoprotein composition. Special attention must, therefore, be paid to these subjects given the atherosclerotic potency of lipid and lipoprotein disorders.

Retour d’expérience des attentats du 13 novembre 2015. Rôle d’une cellule de crise hospitalière

Les attentats du 13 novembre 2015 ont donné lieu à une mobilisation sans précédent des établissements hospitaliers. Le groupe hospitalier Pitié Salpêtrière, particulièrement impliqué dans la prise en charge des victimes, a activé durant cette nuit tragique son Plan Blanc et mis en application tous les principes préalablement définis permettant d’assurer un soutien logistique à la prise en charge médicale. La cellule de crise réunie autour du directeur de l’établissement a piloté cette mise en oeuvre dans ses différentes dimensions: mobilisation des ressources humaines, activation de toutes les fonctions supports nécessaires (sécurisation du site, approvisionnements, ouverture de lieux d’accueil des familles et des personnels) et enfin gestion des familles. Rétrospectivement, cette mise en oeuvre a été globalement conforme aux dispositions préétablies et efficace en termes de soutien à l’activité médicale d’urgence pratiquée. Elle suggère cependant une analyse critique des points de faiblesse afin d’améliorer les procédures du Plan Blanc, dans un contexte actuel que l’on sait particulièrement à risque.

Functional role of a polymorphism in the Pannexin1 gene in collagen-induced platelet aggregation

Pannexin1 (Panx1) forms ATP channels that play a critical role in the immune response by reinforcing purinergic signal amplification in the immune synapse. Platelets express Panx1 and given the importance of ATP release in platelets, we investigated Panx1 function in platelet aggregation and the potential impact of genetic polymorphisms on Panx1 channels. We show here that Panx1 forms ATP release channels in human platelets and that inhibiting Panx1 channel function with probenecid, mefloquine or specific (10)Panx1 peptides reduces collagen-induced platelet aggregation but not the response induced by arachidonic acid or ADP. These results were confirmed using Panx1-/- platelets. Natural variations have been described in the human Panx1 gene, which are predicted to induce non-conservative amino acid substitutions in its coding sequence. Healthy subjects homozygous for Panx1-400C, display enhanced platelet reactivity in response to collagen compared with those bearing the Panx1-400A allele. Conversely, the frequency of Panx1-400C homozygotes was increased among cardiovascular patients with hyper-reactive platelets compared with patients with hypo-reactive platelets. Exogenous expression of polymorphic Panx1 channels in a Panx-deficient cell line revealed increased basal and stimulated ATP release from cells transfected with Panx1-400C channels compared with Panx1-400A expressing transfectants. In conclusion, we demonstrate a specific role for Panx1 channels in the signalling pathway leading to collagen-induced platelet aggregation. Our study further identifies for the first time an association between a Panx1-400A>C genetic polymorphism and collagen-induced platelet reactivity. The Panx1-400C variant encodes for a gain-of-function channel that may adversely affect atherothrombosis by specifically enhancing collagen-induced ATP release and platelet aggregation.

Titration of the gap junction protein Connexin43 reduces atherogenesis

Ubiquitous reduction of the gap junction protein Connexin43 (Cx43) in mice provides beneficial effects on progression and composition of atherosclerotic lesions. Cx43 is expressed in multiple atheroma-associated cells but its function in each cell type is not known. To examine specifically the role of Cx43 in immune cells, we have lethally irradiated low-density lipoprotein receptor-deficient mice and reconstituted with Cx43+/+, Cx43+/- or Cx43-/- haematopoietic fetal liver cells. Progression of atherosclerosis was significantly lower in aortic roots of Cx43+/- chimeras compared with Cx43+/+ and Cx43-/- chimeras, and their plaques contained significantly less neutrophils. The relative proportion of circulating leukocytes was similar between the three groups. Interestingly, the chemoattraction of neutrophils, which did not express Cx43, was reduced in response to supernatant secreted by Cx43+/- macrophages in comparison with the ones of Cx43+/+ and Cx43-/- macrophages. Cx43+/- macrophages did not differ from Cx43+/+ and Cx43-/- macrophages in terms of M1/M2 polarisation but show modified gene expression for a variety chemokines and complement components. In conclusion, titration of Cx43 expression in bone marrow-derived macrophages reduces atherosclerotic plaque formation and chemoattraction of neutrophils to the lesions.

[Cavitating pulmonary infarcts revealing thromboembolic pulmonary hypertension]

Several etiologies are involved in the pathogenesis of cavitating pulmonary disease including neoplastic, infectious or inflammatory processes. Another is pulmonary infarction associated with venous thromboembolism. The lung cavities tend to be located peripherally and are the result of pulmonary embolism. We report the case of a woman with chronic thromboembolic pulmonary hypertension (CTEPH), associated with familial thrombophilia, revealed by cavitating pulmonary infarcts. CTEPH is sometimes diagnosed during an episode of recurrent pulmonary embolism following previously unnoticed lesions. Thrombophilias such as isolated elevated factor VIII are risk factors for CTEPH.

In vivo chemical investigation of human skin using a confocal Raman fiber optic microprobe

To evaluate the potential of a new in vivo confocal Raman microprobe, we undertake a pilot study in human skin. A fiber optic probe is operated with a 633-nm laser and trials are conducted in healthy volunteers. We examine changes in molecular composition and structure of the stratum corneum, from different volunteers, from different anatomical sites and skin layers. Main spectral variations are detected in the following regions: 800 to 900 cm(-1) (amino acids); 1200 to 1290 cm(-1) (proteins); and 1030 to 1130 cm(-1), 1300 to 1450 cm(-1), and 2800 to 2900 cm(-1) (lipids). Curve fitting of the amide 1 region performs in detail protein secondary structural variations of the amide 1 band. Protein conformation is also found to vary depending on the anatomical site and volunteer. Similar analysis of the 730- to 1170-cm(-1) spectral window reveals a different organization of lamellar lipids: gel for forearm and palm, and liquid-crystalline phase for fingertips. All these variations result from changes in the stratum corneum components such as natural moisturizing factor (NMF), lipids (namely ceramides), and water. Hierarchical clustering classification is also performed to sort out Raman data obtained from different subjects. Further improvement of the confocal probe would be to adapt a 360-deg configuration enabling access to other anatomical sites.

A peptide derived from melanocytic protein gp100 and presented by HLA-B35 is recognized by autologous cytolytic T lymphocytes on melanoma cells

A panel of autologous cytolytic T lymphocyte (CTL) clones have been isolated from blood lymphocytes of a melanoma patient after in vitro stimulation with autologous tumor cells. We previously reported the molecular definition of three distinct antigens recognized by some of these CTL clones. We describe here, the identification of a fourth antigenic peptide expressed by this melanoma line and recognized by a CTL clone restricted by HLA-B*3503. The antigenic peptide, which is nine-amino acid long, has the sequence LPHSSSHWL and is derived from melanocyte differentiation antigen gp100. As HLA-B35 is one of the most frequent HLA-B alleles, being present in 20% of the Caucasian individuals, this peptide may be a good target for peptide-based immunotherapy of melanoma.

The building blocks of planets within the 'terrestrial' region of protoplanetary disks

Our Solar System was formed from a cloud of gas and dust. Most of the dust mass is contained in amorphous silicates, yet crystalline silicates are abundant throughout the Solar System, reflecting the thermal and chemical alteration of solids during planet formation. (Even primitive bodies such as comets contain crystalline silicates.) Little is known about the evolution of the dust that forms Earth-like planets. Here we report spatially resolved detections and compositional analyses of these building blocks in the innermost two astronomical units of three proto-planetary disks. We find the dust in these regions to be highly crystallized, more so than any other dust observed in young stars until now. In addition, the outer region of one star has equal amounts of pyroxene and olivine, whereas the inner regions are dominated by olivine. The spectral shape of the inner-disk spectra shows surprising similarity with Solar System comets. Radial-mixing models naturally explain this resemblance as well as the gradient in chemical composition. Our observations imply that silicates crystallize before any terrestrial planets are formed, consistent with the composition of meteorites in the Solar System.

Insulin resistance modifies plasma fatty acid distribution and decreases cardiac tolerance to in vivo ischaemia/reperfusion in rats

1. The early stage of insulin resistance, also termed the 'prediabetic state', is characterized by the development of hyperinsulinaemia, which maintains normoglycaemia under fasting conditions. The metabolic disorders induced in myocardial cells during this stage of the disease may constitute a basis for an alteration of the tolerance of the heart to ischaemia and reperfusion. 2. To test this hypothesis, male Wistar rats were fed a 66% fructose diet for 4 weeks, inducing a prediabetic state. Rats were then subjected to in vivo left coronary artery ligation followed by reperfusion. Blood samples were collected for plasma lipid profile determination. 3. The prediabetic state significantly increased the severity of ischaemia-induced arrhythmias (arrhythmia score 1.4 +/- 0.2 vs 2.0 +/- 0.0 in control and fructose-fed rats, respectively; P < 0.05) and the size of infarction (infarct size 41.2 +/- 3.0 vs 56.0 +/- 2.0% in control and fructose-fed rats, respectively; P < 0.01). This alteration of the tolerance to in vivo ischaemia/reperfusion may be the consequence of an increase in mono-unsaturated fatty acids and a decrease in omega3 polyunsaturated fatty acids in fructose-fed-rats. 4. In conclusion, because it is known that the prediabetic state increases the incidence of cardiovascular diseases by promoting coronaropathy, our study suggests that this metabolic disorder may also affect the prognosis of heart disease by decreasing the tolerance of cardiomyocytes to ischaemic insults.

[The effect of argan oil on heart function during ischemia and reperfusion]

The aim of this study was to evaluate the effect of organ oil on isolated heart function before and after ischemia and on the activity of cardiac antioxidant enzymes. 16 Wistar rats were divided into 2 groups; control group and treated group receiving 5 mL/kg/day of organ oil. After 8 weeks of treatment, hearts were perfused and subjected to a global ischemia followed by reperfusion. Activity of cardiac antioxidant enzymes was assessed in freeze-clamped hearts at the end of reperfusion. Results showed that organ oil induces: 1--damage to heart function during the preischemic period, 2--decreased functional recovery during reperfusion and 3--significant increase in catalase activity. It seems that, in our experimental conditions, organ oil increases heart sensitivity to ischemia and reperfusion. However, the mechanism involved has yet to be understood.

Cysteinyl leukotrienes modulate angiotensin II constrictor effects on aortas from streptozotocin-induced diabetic rats

Angiotensin II (Ang II) is a vasopressor peptide involved in the pathogenesis of cardiovascular diseases associated with diabetes mellitus. We have previously reported that the 5-lipoxygenase-derived products, particularly the cysteinyl leukotrienes (CysLTs), are involved in Ang II-induced contraction. In this study, we demonstrated that CysLTs contribute to the contraction elicited by Ang II in isolated aortas from streptozotocin-induced diabetic (SS) rats but not from insulin-treated diabetic rats, fructose-fed rats, or control rats. In an organ bath, pretreatment with the 5-lipoxygenase inhibitor (AA861, 10 micromol/L) reduced by 37.6+/-8.2% and 30.1+/-10.9% the Ang II-induced contractions in intact and endothelium-denuded aortic rings, respectively, from SS rats. In contrast, the CysLT(1) receptor antagonist (MK571, 1 micromol/L) or the dual CysLT(1)/CysLT(2) receptor antagonist (BAY-u9773, 0.1 micromol/L) did not affect Ang II-induced contraction. In addition, Ang II induced a 6.2+/-1.5-fold increase in CysLT release through the stimulation of the Ang II type 1 receptor. Furthermore, the urinary excretion of leukotriene E(4) was increased in SS rats (leukotriene E(4), 13.7+/-2.9 ng/24 h [SS rats, n=10] versus 1.5+/-0.5 ng/24 h [control rats, n=6]; P<0.0004). These data suggest the activation of the 5-lipoxygenase pathway in SS rats and the involvement of 5-lipoxygenase-derived products, particularly the CysLTs, in Ang II-induced contraction in aortas from SS rats through stimulation of CysLT receptors different from the well-characterized CysLT(1) or CysLT(2) receptor.

Emulsions containing partially water-miscible solvents for the preparation of drug nanosuspensions

The aim of this study was to investigate the feasibility of partially water-miscible solvents, such as benzyl alcohol, butyl lactate and triacetin, to prepare drug nanosuspensions by a solvent quenching technique. Mitotane, which possesses very poor water solubility and low bioavailability, was used as model drug. Preparation was by emulsifying an organic solution of the drug in an aqueous solution of a stabilising agent followed by rapid displacement of the solvent from the internal into the external phase, provoking solid particle formation. To verify the influence of emulsion droplet size on the drug particle size, 0.1 or 0.2% of different emulsifiers (Tween 80, caprylyl-capryl glucoside or lecithin) and different homogenisation conditions (Ultra Turrax or a high pressure homogenizer at 200 or 1000 bar for three cycles) were used. In general, emulsion droplet size decreased with high pressure homogenization and on increasing the number of cycles. The size of drug particles, obtained after adding water at a constant rate, was dependent on the droplet size in the emulsion. Drug particles of approximately 80 nm were obtained using butyl lactate, supporting the hypothesis that drug particle formation by the emulsification diffusion process involves generating regions of local supersaturation. Because of the increase in available surface area, the dissolution rate of diaultrafiltrated suspensions increased greatly compared to commercial product.

Differential processing of class-I-restricted epitopes by the standard proteasome and the immunoproteasome

Upon exposure to IFN-gamma, the standard proteasome is replaced by the immunoproteasome, which contains LMP2, LMP7 and MECL1, and is considered more efficient at producing antigenic peptides presented to CD8(+) T cells. This view has been challenged this year by reports showing that some epitopes, mainly of self origin, are not processed by the immunoproteasome and that mature dendritic cells constitutively express immunoproteasomes and therefore cannot efficiently present such epitopes.

Cardiac toxicity of singlet oxygen: implication in reperfusion injury

Oxygen-derived free radicals (O2.-, H2O2, and .OH) that are produced during postischemic reperfusion are currently suspected to be involved in the pathogenesis of tissue injury. Another reactive oxygen species, the electronically excited molecular oxygen (1O2), is of increasing interest in the area of experimental research in cardiology. In this review are discussed the main potential sources of singlet oxygen in the organism, particularly in the myocardium, the various cardiovascular cytotoxic effects induced by this reactive oxygen intermediate, and the growing evidence of its involvement in ischemia/reperfusion injury.

Determinants of nurses' adherence to universal precautions for venipunctures

OBJECTIVES

The aim of this study was to predict and explain nurses' adherence to Universal Precautions (UPs) when performing venipunctures.

METHODS

Data were gathered from 156 registered nurses working at a regional hospital. A self-administered questionnaire assessing the psychosocial variables (intention, attitude, subjective norm, perceived control, etc) was completed at baseline, and behavior was self-reported 3 months later.

RESULTS

The regression of intention on the variables yielded an adjusted R(2) of 0.68, with perceived barriers (beta =.62, P <.001), social norm (beta =.17, P <.01), and personal normative belief (beta =.19, P <.01) being the significant variables. With respect to the 3-month follow-up, 28% of the variance associated with UPs adherence was explained by intention (beta =.37, P <.001) and perceived behavioral control (beta =.23, P <.05). Moreover, high (n = 116) and low intenders (n = 40) differed on several normative beliefs (P =.0003) and perceived barriers (P =.0001).

CONCLUSIONS

It is suggested that perception of control, assessed either globally or by means of a belief-based measure, is a key factor in adherence. Specifically, the perceived difficulties associated with adherence to UPs appear to be related to a nurse's training on UPs and to the existence of suboptimal working conditions.

Scaling of crack surfaces and implications for fracture mechanics

The scaling laws describing the roughness development of crack surfaces are incorporated into the Griffith criterion. We show that, in the case of a Family-Vicsek scaling, the energy balance leads to a purely elastic brittle behavior. On the contrary, it appears that an anomalous scaling reflects an R-curve behavior associated with a size effect of the critical resistance to crack growth in agreement with the fracture process of heterogeneous brittle materials exhibiting a microcracking damage.