Towards high-throughput identification of endocrine disrupting compounds with mass spectrometry

High-mass matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) combined with chemical cross-linking has the ability to monitor the ligand-dependent dimerization of the human estrogen receptor α ligand binding domain (hERα LBD) in solution. Because only ER ligands enhance the homodimer abundance, we evaluated the ability of this label-free approach for identifying endocrine disrupting compounds (EDCs) in a high-throughput manner. This was achieved by combining an automated liquid handler with an automated MS acquisition procedure, which allowed a five-fold gain in operator time compared to a fully manual approach. To detect ligand binding with enough confidence, the receptor has to be incubated with at least a 10 μM concentration of the test compound. Based on the increase of the measured homodimer intensity, eight compounds with a relative binding affinity (RBA, relative to the natural hormone estradiol) >7% were identified as ER ligands among the 28 chemicals tested. Two other compounds, quercetin and 4-tert-amylphenol, were also identified as ER ligands, although their RBAs have been reported to be only 0.01% and 0.000055%, respectively. This suggests that these two ligands have a higher affinity for hERα LBD than reported in the literature. The high-mass MALDI approach thus allows identifying high affinity EDCs in an efficient way.     

Laparoscopic reconstruction after esophageal resection for perforation: a new surgical approach

The authors present 2 cases of esophageal perforation treated using a new 2-step approach, consisting of esophageal resection and delayed reconstruction of the digestive tract after laparoscopic preparation and transposition of the stomach. The method is characterized by the minimally invasive insertion of a gastric tube through the precardial esophageal stump for postoperative enteral nutrition, and by the use of a laparoscopic method in the reconstruction step for gastrolysis and transposition of the stomach. The benefits lie in the opportunity for enteral feeding preparatory to the reconstruction, with no need for any gastrostomy or jejunostomy, and with fewer complications and a better recovery after reconstruction surgery thanks to the use of a laparoscopic method instead of a laparotomy.     

Surgery for palliation and treatment of advanced breast cancer

The palliative benefits of surgery in patients with stage IV breast cancer have long been appreciated. Optimizing patient comfort and quality of life are critically important goals in these patients, most of whom have limited life expectancy. Advancements in reconstructive techniques have allowed for closure of extensive and complex defects of the chest wall and surrounding soft tissue without the need to sacrifice oncologic goals. However, care must be taken to weigh the extent of surgery and reconstruction against the possible delay to radiation and systemic treatment, as multimodality therapy offers the best chance for durable symptom management in these challenging patients.The emergence of increasingly effective systemic therapies has also created the need to address resectable primary sites as well as distant sites in women with metastatic breast cancer, as many can expect to survive for many years with stable disease. Several models of cancer and metastatic progression have been proposed. However, the significant challenge of identifying those patients who may most gain from local surgery remains. This question is ideally suited for multi-institutional prospective, randomized controlled trials, as no single institution alone has sufficient experience to definitively address these issues. Careful consideration must be given to incorporating disease extent, sites of involvement, patient comorbidities and rate of progression into the study design. Furthermore, genomic and proteomic phenotyping of tumors may in future prove to be important criteria for patient selection for “targeted” surgical therapy and must be a fundamental component of these studies. The new generation of prospective clinical trials of surgery for stage IV breast cancer patients may identify a subset of women who may benefit from incorporating surgery into a multimodality treatment plan, leading to improved quality of life, survival and potential cure in women with advanced disease.     

Sex differences in the ovine fetal cortisol response to stress

This study tested the hypothesis that the sexually dimorphic adrenocortical response to stress is already established before birth. Chronically instrumented late gestation pregnant sheep carrying 16 male and 15 female age-matched singleton fetuses were subjected to an acute episode of hypoxic stress. Maternal and fetal blood gases, adrenocorticotrophic hormone (ACTH), and cortisol were measured. In addition, six male and six female fetuses received the ACTH analog, Synacthen, and plasma cortisol was measured. During hypoxic stress, the increment in plasma cortisol was 2-fold greater in male versus females fetuses (30.6 ± 3.2 versus 14.3 ± 2.0 ng/mL; p < 0.001) mediated, in part, by greater adrenocortical sensitivity to ACTH. The data support the hypothesis tested and show that sex-specific differences in the cortisol stress response are present before birth with the output of cortisol being much greater in male than in female fetuses.     

Impaired CTLA-4 responses in COPD are associated with systemic inflammation

Systemic inflammation is a feature of chronic obstructive pulmo- nary disease （COPD）. Defects in T cell-mediated anti-inflamma- tory pathways such as cytotoxic T lymphocyte antigen-4 （CTLA- 4） may promote damaging inflammation. This study provides novel data implicating the impaired induction of an anti-inflam- matory molecule, CTLA-4 in the elevated inflammation observed in COPD patients. Low induction of CTLA-4 in COPD patients paralleled increased markers of systemic inflammation ex vivo and increased T-cell responses to a bacterial superantigen, staphylo- coccal enterotoxin-B （SEB） in vitro. This mechanism may explain the increased inflammation in COPD patients.     

The proportion and function of peripheral myeloid-derived suppressor cells do not correlate with systemic inflammation in chronic obstructive pulmonary disease

Myeloid-derived suppressor cells (MDSC) have been implicated in the regulation of chronic inflammation. Chronic obstructive pulmonary disease (COPD) involves persistent inflammation, but the role of MDSC has not been explored. Here, proportions of MDSC (CD14⁻HLA-DR⁻CD33⁺CD11b⁺ cells) were quantified in peripheral blood mononuclear cells (PBMC) isolated from patients with ‘stable’ COPD (n = 12), smokers with no evidence of COPD (n = 11) and healthy non-smokers (n = 11). The proportions of MDSC were similar in all groups. MDSC function was assessed by comparing T-cell and cytokine responses of whole and MDSC-depleted PBMC stimulated with Staphylococcus enterotoxin-B (SEB). Depletion of MDSC did not enhance CD4⁺ or CD8⁺ T-cell activation and proliferation, or alter IFNγ and IL-17 production in response to SEB. However production of TGFβ decreased after depletion of MDSC, so MDSC may be a source of this cytokine. In conclusion, COPD was not associated with perturbations in the proportion or function of MDSC in peripheral blood.