Genome-Wide Association Study on Three Behaviors Tested in an Open Field in Heterogeneous Stock Rats Identifies Multiple Loci Implicated in Psychiatric Disorders

Many personality traits are influenced by genetic factors. Rodents models provide an efficient system for analyzing genetic contribution to these traits. Using 1,246 adolescent heterogeneous stock (HS) male and female rats, we conducted a genome-wide association study (GWAS) of behaviors measured in an open field, including locomotion, novel object interaction, and social interaction. We identified 30 genome-wide significant quantitative trait loci (QTL). Using multiple criteria, including the presence of high impact genomic variants and co-localization of cis-eQTL, we identified 17 candidate genes (Adarb2, Ankrd26, Cacna1c, Cacng4, Clock, Ctu2, Cyp26b1, Dnah9, Gda, Grxcr1, Eva1a, Fam114a1, Kcnj9, Mlf2, Rab27b, Sec11a, and Ube2h) for these traits. Many of these genes have been implicated by human GWAS of various psychiatric or drug abuse related traits. In addition, there are other candidate genes that likely represent novel findings that can be the catalyst for future molecular and genetic insights into human psychiatric diseases. Together, these findings provide strong support for the use of the HS population to study psychiatric disorders.

Impact of preoperative radiotherapy on head and neck free flap reconstruction: a report on 429 cases

BACKGROUND

The primary objective of this study was to evaluate the impact of preoperative radiotherapy on the outcomes of head and neck microvascular reconstruction. The secondary objective was to assess the specific effects of irradiation doses (IDs) ≥60 Gy on the outcomes of head and neck microvascular reconstruction.

METHODS

All patients who underwent head and neck free-flap reconstruction in our institution between 2000 and 2010 were included in this retrospective study. A total of 429 patients were enrolled including 136 patients previously irradiated on the head and neck. The impact of preoperative radiotherapy on free-flap success, local and general complications, postoperative mortality, time of decannulation, duration of enteral nutrition and length of stay was assessed in univariate and multivariate analyses.

RESULTS

In multivariate analysis, preoperative radiotherapy (irrespective of ID) was a significant risk factor for fistula formation (p = 0.003) and wound infection (p = 0.005). Previous neck irradiation at doses ≥60 Gy was associated with an increased risk of free-flap failure (p = 0.04), overall local complications (p = 0.05), haematoma (p = 0.04) and longer duration of enteral nutrition (p = 0.006) and hospital stay (p = 0.004).

CONCLUSIONS

Preoperative radiotherapy, particularly for ID ≥ 60 Gy, is one of the main determinants of the outcomes of head and neck microvascular reconstruction.

[Total pharyngolaryngectomy in the 21st century: indications, oncologic and functional outcomes]

INTRODUCTION

The development of laryngeal preservation protocols has considerably modified the indications for total (pharyngo-)laryngectomy (TPL). The objectives of our study are to analyze the current indications for TPL and to evaluate the oncologic and functional outcomes after TPL and their predictive factors.

METHODS

All patients who underwent TPL for squamous cell carcinoma of the larynx or hypopharynx, at our institution, between 2000 and 2009, were included in this retrospective study. Predictive factors of oncologic and functional outcomes were assessed in univariate and multivariate analyzes.

RESULTS

A total of 130 patients were enrolled in our study including 119 men and 11 women, with a mean age of 65.9 years. TPL was realized for salvage in 65 patients. Extra-laryngeal tumor extension (n = 42) was the main indication for TPL in the 65 remaining patients. Overall survival was 49 and 41% at 3 and 5 years respectively. In multivariate analysis, primary tumor site (hypopharynx in comparison to larynx; p = 0.04) has a significant pejorative impact on overall survival. Oral alimentation (no enteral nutrition) was recovered successfully by 94% of the patients. In multivariate analysis, primary tumor site (hypopharynx) has a significant pejorative impact on functional results (deglutition: p < 0.0001; phonation: p = 0.03).

CONCLUSION

Primary tumor site is one of the main predictive factor of oncologic and functional outcomes after TPL.

Structural and functional characterization of H protein mutants of the glycine decarboxylase complex

The mitochondrial glycine decarboxylase complex (GDC) consists of four component enzymes (P, H, T, and L proteins) involved in the breakdown of glycine. In order to investigate structural interactions involved in the stabilization of the methylamine-loaded H protein (a transient species in the GDC reaction), we designed several mutants of H apoprotein. Structural analysis of the wild-type and mutants of H apoprotein emphasized the necessity to carefully assess, by biophysical techniques, the correct folding of mutated proteins prior to investigate their biochemical properties. The correctly folded wild-type and mutants of H apoprotein were in vitro lipoylated and then characterized in the context of GDC reaction by studying the reconstituted complex and partial reactions. We showed that Val(62) and Ala(64), surrounding the lipoyl-lysine, play an important role in the molecular events that govern the reaction between P and H protein but do not intervene in the recognition of the binding site of lipoic acid by lipoyl ligase. The biochemical results obtained with the HE14A mutant of H protein pointed out the major role of the Glu(14) amino acid residue in the GDC catalysis and highlighted the importance of the ionic and hydrogen bounds in the hydrophobic cleft of H protein for the stabilization of the methylamine-loaded lipoyl arm.