Sagittal abdominal diameter is a better predictor than body mass index for duration of laparoscopic left colectomy.

BACKGROUND: Visceral obesity (VO) increases technical difficulty in laparoscopic surgery. The body mass index (BMI) does not always correlate to intra-abdominal fat distribution. Our hypothesis was that simple anthropometric measures that reflect VO, could predict technical difficulty in laparoscopic colorectal surgery, as reflected by the operative time, more accurately than the BMI. METHODS: Charts of all consecutive patients who underwent laparoscopic left colon resection in our institution between 2007 and 2010 were reviewed retrospectively. On a preoperative CT scan, anthropometric measures were taken on an axial plane at the L4-L5 level. Demographic, operative and anthropometric CT measures were correlated with the operative time. Logistic regression analysis was performed to assess the value of anthropometric CT measures or BMI to predict the duration of the colectomy. RESULTS: 121 patients with elective left colon resection for benign (56%) or malignant disease (44%) were included. There were 74 sigmoid resections (61%), 21 left hemicolectomies (17%) and 26 low anterior resections (22%). A longer sagittal abdominal diameter (≥24.8 cm) was significantly associated with longer corrected operative time (248 vs. 228 min, p = 0.043). In multivariate analysis, greater sagittal abdominal diameter, sagittal internal diameter and abdominal perimeter were significantly associated with longer operative time. No significant association was found for the BMI neither in univariate nor in multivariate analysis. CONCLUSIONS: This study suggests that simple linear measures taken on a CT scan, such as sagittal abdominal diameter, sagittal internal diameter and abdominal perimeter, may predict longer operative time in laparoscopic left colonic resections more accurately than BMI.

Contribution of Intronic miR-338-3p and Its Hosting Gene AATK to Compensatory β-Cell Mass Expansion.

The elucidation of the mechanisms directing β-cell mass regeneration and maintenance is of interest, because the deficit of β-cell mass contributes to diabetes onset and progression. We previously found that the level of the microRNA (miRNA) miR-338-3p is decreased in pancreatic islets from rodent models displaying insulin resistance and compensatory β-cell mass expansion, including pregnant rats, diet-induced obese mice, and db/db mice. Transfection of rat islet cells with oligonucleotides that specifically block miR-338-3p activity increased the fraction of proliferating β-cells in vitro and promoted survival under proapoptotic conditions without affecting the capacity of β-cells to release insulin in response to glucose. Here, we evaluated the role of miR-338-3p in vivo by injecting mice with an adeno-associated viral vector permitting specific sequestration of this miRNA in β-cells. We found that the adeno-associated viral construct increased the fraction of proliferating β-cells confirming the data obtained in vitro. miR-338-3p is generated from an intron of the gene coding for apoptosis-associated tyrosine kinase (AATK). Similarly to miR-338-3p, we found that AATK is down-regulated in rat and human islets and INS832/13 β-cells in the presence of the cAMP-raising agents exendin-4, estradiol, and a G-protein-coupled Receptor 30 agonist. Moreover, AATK expression is reduced in islets of insulin resistant animal models and selective silencing of AATK in INS832/13 cells by RNA interference promoted β-cell proliferation. The results point to a coordinated reduction of miR-338-3p and AATK under insulin resistance conditions and provide evidence for a cooperative action of the miRNA and its hosting gene in compensatory β-cell mass expansion.

Use of the dried blood spot sampling process coupled with fast gas chromatography and negative-ion chemical ionization tandem mass spectrometry: application to fluoxetine, norfluoxetine, reboxetine, and paroxetine analysis.

The objective of this work was to combine the advantages of the dried blood spot (DBS) sampling process with the highly sensitive and selective negative-ion chemical ionization tandem mass spectrometry (NICI-MS-MS) to analyze for recent antidepressants including fluoxetine, norfluoxetine, reboxetine, and paroxetine from micro whole blood samples (i.e., 10 microL). Before analysis, DBS samples were punched out, and antidepressants were simultaneously extracted and derivatized in a single step by use of pentafluoropropionic acid anhydride and 0.02% triethylamine in butyl chloride for 30 min at 60 degrees C under ultrasonication. Derivatives were then separated on a gas chromatograph coupled with a triple-quadrupole mass spectrometer operating in negative selected reaction monitoring mode for a total run time of 5 min. To establish the validity of the method, trueness, precision, and selectivity were determined on the basis of the guidelines of the "Société Française des Sciences et des Techniques Pharmaceutiques" (SFSTP). The assay was found to be linear in the concentration ranges 1 to 500 ng mL(-1) for fluoxetine and norfluoxetine and 20 to 500 ng mL(-1) for reboxetine and paroxetine. Despite the small sampling volume, the limit of detection was estimated at 20 pg mL(-1) for all the analytes. The stability of DBS was also evaluated at -20 degrees C, 4 degrees C, 25 degrees C, and 40 degrees C for up to 30 days. Furthermore, the method was successfully applied to a pharmacokinetic investigation performed on a healthy volunteer after oral administration of a single 40-mg dose of fluoxetine. Thus, this validated DBS method combines an extractive-derivative single step with a fast and sensitive GC-NICI-MS-MS technique. Using microliter blood samples, this procedure offers a patient-friendly tool in many biomedical fields such as checking treatment adherence, therapeutic drug monitoring, toxicological analyses, or pharmacokinetic studies.

Agricultural land use and human presence around breeding sites increase stress-hormone levels and decrease body mass in barn owl nestlings.

Human activities can have a suite of positive and negative effects on animals and thus can affect various life history parameters. Human presence and agricultural practice can be perceived as stressors to which animals react with the secretion of glucocorticoids. The acute short-term secretion of glucocorticoids is considered beneficial and helps an animal to redirect energy and behaviour to cope with a critical situation. However, a long-term increase of glucocorticoids can impair e.g. growth and immune functions. We investigated how nestling barn owls (Tyto alba) are affected by the surrounding landscape and by human activities around their nest sites. We studied these effects on two response levels: (a) the physiological level of the hypothalamus-pituitary-adrenal axis, represented by baseline concentrations of corticosterone and the concentration attained by a standardized stressor; (b) fitness parameters: growth of the nestlings and breeding performance. Nestlings growing up in intensively cultivated areas showed increased baseline corticosterone levels late in the season and had an increased corticosterone release after a stressful event, while their body mass was decreased. Nestlings experiencing frequent anthropogenic disturbance had elevated baseline corticosterone levels, an increased corticosterone stress response and a lower body mass. Finally, breeding performance was better in structurally more diverse landscapes. In conclusion, anthropogenic disturbance affects offspring quality rather than quantity, whereas agricultural practices affect both life history traits.

The 16p11.2 rearrangments genetic paradigms for obesity and neurodevelopmental disorders.

Recent discoveries of recurrent and reciprocal Copy Number Variants (CNVs) using genome- wide studies have led to a new understanding of the etiology of neuropsychiatric disorders. CNVs represent loss (deletion) or gain (duplication) of genomic material. This thesis work is focused on CNVs at the 16p11.2 BP4-BP5 locus, which are among the most frequent etiologies of neurodevelopmental disorders and have been associated with Autism Spectrum Disorders (ASD), schizophrenia, cognitive impairment, alterations of brain size as well as obesity and underweight. Because deletion and duplication of the 16p11.2 locus occur frequently and recurrently (with the same breakpoints), CNVs at this locus represent a powerful paradigm to understand how a genomic region may modulate cognitive and behavioral traits as well as the relationship and shared mechanisms between distinct psychiatric diagnoses such as ASD and schizophrenia. The present dissertation includes three studies: 1) The first project aims at identifying structural brain-imaging endophenotypes in 16p11.2 CNVs carriers at risk for ASD and schizophrenia. The results show that gene dosage at the 16p11.2 locus modulates global brain volumes and neural circuitry, including the reward system, language and social cognition circuits. 2) The second investigates the neuropsychological profile in 16p11.2 deletion and duplication carriers. While deletion carriers show specific deficits in language and inhibition, the profile of duplication carriers is devoid of specific weaknesses and presents enhanced performance in a verbal memory task. 3) The third study on food-related behaviors in 16p11.2 deletion and duplication carriers shows that alterations of the reponse to satiety are present in CNV carriers before the onset of obesity, pointing toward a potential mechanism driving the Body Mass Index increase in deletion carriers. Dysfunctions in the reward system and dopaminergic circuitries could represent a common mechanism playing a role in the phenotype and could be investigated in future studies. Our data strongly suggest that complex cognitive traits correlate to gene dosage in humans. Larger studies including expression data would allow elucidating the contribution of specific genes to these different gene dosage effects. In conclusion, a systematic and careful investigation of cognitive, behavioral and intermediate phenotypes using a gene dosage paradigm has allowed us to advance our understanding of the 16p11.2 BP4-BP5 locus and its effects on neurodevelopment. -- La récente découverte de variations du nombre de copies (CNVs pour 'copy number variants') dans le génome humain a amélioré nos connaissances sur l'étiologie des troubles neuropsychiatriques. Un CNV représente une perte (délétion) ou un gain (duplication) de matériel génétique sur un segment chromosomique. Ce travail de thèse est focalisé sur les CNVs réciproques (délétion et duplication) dans la région 16p11.2 BP4-BP5. Ces CNVs sont une cause fréquente de troubles neurodéveloppementaux et ont été associés à des phénotypes « en miroir » tels que obésité/sous-poids ou macro/microcéphalie mais aussi aux troubles du spectre autistique (TSA), à la schizophrénie et au retard de développement/déficience intellectuelle. La fréquence et la récurrence de la délétion et de la duplication aux mêmes points de cassure font de ces CNVs un paradigme unique pour étudier la relation entre dosage génique et les traits cognitifs et comportementaux, ainsi que les mécanismes partagés par des troubles psychiatriques apparemment distincts tels que les TSA et la schizophrénie. Ce travail de thèse comporte trois études distinctes : 1) l'étude en neuroimagerie structurelle identifie les endophénotypes chez les porteurs de la délétion ou de la duplication. Les résultats montrent une influence du dosage génique sur le volume cérébral total et certaines structures dans les systèmes de récompense, du langage et de la cognition sociale. 2) L'étude des profils neuropsychologiques chez les porteurs de la délétion ou de la duplication montre que la délétion est associée à des troubles spécifiques du langage et de l'inhibition alors que les porteurs de la duplication ne montrent pas de faiblesse spécifique mais des performances mnésiques verbales supérieures à leur niveau cognitif global. 3) L'étude sur les comportements alimentaires met en évidence une altération de la réponse à la satiété qui est présente avant l'apparition de l'obésité. Un dysfonctionnement dans le système de récompense et les circuits dopaminergiques pourrait représenter un mécanisme commun aux différents phénotypes observés chez ces individus porteurs de CNVs au locus 16p11.2. En conclusion, l'utilisation du dosage génique comme outil d'investigation des phénotypes cliniques et endophénotypes nous a permis de mieux comprendre le rôle de la région 16p11.2 BP4-BP5 dans le neurodéveloppement.

Blood monitoring of perfluorocarbon compounds (F-tert-butylcyclohexane, perfluoromethyldecalin and perfluorodecalin) by headspace-gas chromatography-tandem mass spectrometry.

A headspace-gas chromatography-tandem mass spectrometry (HS-GC-MS/MS) method for the trace measurement of perfluorocarbon compounds (PFCs) in blood was developed. Due to oxygen carrying capabilities of PFCs, application to doping and sports misuse is speculated. This study was therefore extended to perform validation methods for F-tert-butylcyclohexane (Oxycyte(®)), perfluoro(methyldecalin) (PFMD) and perfluorodecalin (PFD). The limit of detection of these compounds was established and found to be 1.2µg/mL blood for F-tert-butylcyclohexane, 4.9µg/mL blood for PFMD and 9.6µg/mL blood for PFD. The limit of quantification was assumed to be 12µg/mL blood (F-tert-butylcyclohexane), 48µg/mL blood (PFMD) and 96µg/mL blood (PFD). HS-GC-MS/MS technique allows detection from 1000 to 10,000 times lower than the estimated required dose to ensure a biological effect for the investigated PFCs. Thus, this technique could be used to identify a PFC misuse several hours, maybe days, after the injection or the sporting event. Clinical trials with those compounds are still required to evaluate the validation parameters with the calculated estimations.

Influence of MCHR2 and MCHR2-AS1 Genetic Polymorphisms on Body Mass Index in Psychiatric Patients and In Population-Based Subjects with Present or Past Atypical Depression.

Obesity development during psychotropic treatments represents a major health issue in psychiatry. Melanin-concentrating hormone receptor 2 (MCHR2) is a central receptor involved in energy homeostasis. MCHR2 shares its promoter region with MCHR2-AS1, a long antisense non-coding RNA. The aim of this study was to determine whether tagging single nucleotide polymorphisms (tSNPs) of MCHR2 and MCHR2-AS1 are associated with the body mass index (BMI) in the psychiatric and in the general population. The influence of MCHR2 and MCHR2-AS1 tSNPs on BMI was firstly investigated in a discovery psychiatric sample (n1 = 474). Positive results were tested for replication in two other psychiatric samples (n2 = 164, n3 = 178) and in two population-based samples (CoLaus, n4 = 5409; GIANT, n5 = 113809). In the discovery sample, TT carriers of rs7754794C>T had 1.08 kg/m2 (p = 0.04) lower BMI as compared to C-allele carriers. This observation was replicated in an independent psychiatric sample (-2.18 kg/m2; p = 0.009). The association of rs7754794C>T and BMI seemed stronger in subjects younger than 45 years (median of age). In the population-based sample, a moderate association was observed (-0.17 kg/m2; p = 0.02) among younger individuals (<45y). Interestingly, this association was totally driven by patients meeting lifetime criteria for atypical depression, i.e. major depressive episodes characterized by symptoms such as an increased appetite. Indeed, patients with atypical depression carrying rs7754794-TT had 1.17 kg/m2 (p = 0.04) lower BMI values as compared to C-allele carriers, the effect being stronger in younger individuals (-2.50 kg/m2; p = 0.03; interaction between rs7754794 and age: p-value = 0.08). This study provides new insights on the possible influence of MCHR2 and/or MCHR2-AS1 on obesity in psychiatric patients and on the pathophysiology of atypical depression.

Development of an enantioselective assay for simultaneous separation of venlafaxine and O-desmethylvenlafaxine by micellar electrokinetic chromatography-tandem mass spectrometry: Application to the analysis of drug-drug interaction.

To-date, there has been no effective chiral capillary electrophoresis-mass spectrometry (CE-MS) method reported for the simultaneous enantioseparation of the antidepressant drug, venlafaxine (VX) and its structurally-similar major metabolite, O-desmethylvenlafaxine (O-DVX). This is mainly due to the difficulty of identifying MS compatible chiral selector, which could provide both high enantioselectivity and sensitive MS detection. In this work, poly-sodium N-undecenoyl-L,L-leucylalaninate (poly-L,L-SULA) was employed as a chiral selector after screening several dipeptide polymeric chiral surfactants. Baseline separation of both O-DVX and VX enantiomers was achieved in 15min after optimizing the buffer pH, poly-L,L-SULA concentration, nebulizer pressure and separation voltage. Calibration curves in spiked plasma (recoveries higher than 80%) were linear over the concentration range 150-5000ng/mL for both VX and O-DVX. The limit of detection (LOD) was found to be as low as 30ng/mL and 21ng/mL for O-DVX and VX, respectively. This method was successfully applied to measure the plasma concentrations of human volunteers receiving VX or O-DVX orally when co-administered without and with indinivar therapy. The results suggest that micellar electrokinetic chromatography electrospray ionization-tandem mass spectrometry (MEKC-ESI-MS/MS) is an effective low cost alternative technique for the pharmacokinetics and pharmacodynamics studies of both O-DVX and VX enantiomers. The technique has potential to identify drug-drug interaction involving VX and O-DVX enantiomers while administering indinivar therapy.