High-Throughput Quantitative Screening of Glucose-Stimulated Insulin Secretion and Insulin Content Using Automated MALDI-TOF Mass Spectrometry.

Type 2 diabetes (T2D) is a metabolic disorder characterized by loss of pancreatic ß-cell function, decreased insulin secretion and increased insulin resistance, that affects more than 537 million people worldwide. Although several treatments are proposed to patients suffering from T2D, long-term control of glycemia remains a challenge. Therefore, identifying new potential drugs and targets that positively affect ß-cell function and insulin secretion remains crucial. Here, we developed an automated approach to allow the identification of new compounds or genes potentially involved in ß-cell function in a 384-well plate format, using the murine ß-cell model Min6. By using MALDI-TOF mass spectrometry, we implemented a high-throughput screening (HTS) strategy based on the automation of a cellular assay allowing the detection of insulin secretion in response to glucose, i.e., the quantitative detection of insulin, in a miniaturized system. As a proof of concept, we screened siRNA targeting well-know ß-cell genes and 1600 chemical compounds and identified several molecules as potential regulators of insulin secretion and/or synthesis, demonstrating that our approach allows HTS of insulin secretion in vitro.

Glucose Regulates m6A Methylation of RNA in Pancreatic Islets.

Type 2 diabetes is characterized by chronic hyperglycemia associated with impaired insulin action and secretion. Although the heritability of type 2 diabetes is high, the environment, including blood components, could play a major role in the development of the disease. Amongst environmental effects, epitranscriptomic modifications have been recently shown to affect gene expression and glucose homeostasis. The epitranscriptome is characterized by reversible chemical changes in RNA, with one of the most prevalent being the m6A methylation of RNA. Since pancreatic ß cells fine tune glucose levels and play a major role in type 2 diabetes physiopathology, we hypothesized that the environment, through variations in blood glucose or blood free fatty acid concentrations, could induce changes in m6A methylation of RNAs in pancreatic ß cells. Here we observe a significant decrease in m6A methylation upon high glucose concentration, both in mice and human islets, associated with altered expression levels of m6A demethylases. In addition, the use of siRNA and/or specific inhibitors against selected m6A enzymes demonstrate that these enzymes modulate the expression of genes involved in pancreatic ß-cell identity and glucose-stimulated insulin secretion. Our data suggest that environmental variations, such as glucose, control m6A methylation in pancreatic ß cells, playing a key role in the control of gene expression and pancreatic ß-cell functions. Our results highlight novel causes and new mechanisms potentially involved in type 2 diabetes physiopathology and may contribute to a better understanding of the etiology of this disease.

Early Tympanoplasty Using a Synthetic Biomembrane for Military-Related Blast Induced Large Tympanic Membrane Perforation.

Introduction: Blast injuries in modern warfare are common, and tympanic perforation is often found. Spontaneous closures of large perforations that encompass greater than 80% of the tympanic surface are rare. Early closure of the tympanic membrane avoids the immediate infectious risk, which potentially complicates the initial management of these war-wounded patients, and allows for safe and early recovery of military activity. This study compared the outcomes of spontaneous closures and early biomembrane myringoplasty in subjects with large blast injury-induced tympanic perforation following a massive explosion. Materials and Methods: This is a retrospective, observational, cohort study military troops with large barotraumatic tympanic membrane perforation. The study investigates early surgical tympanoplasty versus observation for spontaneous closure. The hearing loss, tympanic perforation closure rate, and closure time were noted. Results: Fourteen patients (19 ears) were referred from May 2008 to April 2017, and 6 patients (9 ears) underwent early myringoplasty. A total of 89% (n = 8) and 100% (n = 9) of the ears exhibited successful sealing of the perforation at one and 6 mo, respectively. In contrast, 60% (n = 6) of the 10 ears (8 patients) without initial myringoplasty did not heal spontaneously at 6 mo, and these ears underwent a delayed tympanoplasty procedure. Notably, patients with early myringoplasty suffered lower conductive hearing loss and fewer functional signs remotely. Conclusion: Early myringoplasty using a biomembrane for blast injury-induced large tympanic perforation is a fast and minimally invasive method to achieve earlier tympanic closure and a higher closure rate for safe recovery of activity. It can be performed under general anesthesia concurrently with surgery for additional body-wide trauma. The deployment of ENT surgeons on the battlefield in the French Army has enabled early management of these patients.

ST6GALNAC5 Expression Decreases the Interactions between Breast Cancer Cells and the Human Blood-Brain Barrier.

The ST6GALNAC5 gene that encodes an α2,6-sialyltransferase involved in the biosynthesis of α-series gangliosides, was previously identified as one of the genes that mediate breast cancer metastasis to the brain. We have shown that the expression of ST6GALNAC5 in MDA-MB-231 breast cancer cells resulted in the expression of GD1α ganglioside at the cell surface. By using a human blood-brain barrier in vitro model recently developed, consisting in CD34⁺ derived endothelial cells co-cultivated with pericytes, we show that ST6GALNAC5 expression decreased the interactions between the breast cancer cells and the human blood-brain barrier.

Cancer mortality study among French cement production workers.

PURPOSE: To analyse the mortality and its causes, especially cancer, among French cement production workers. METHODS: A cohort of all workers employed at least 1 year in one of the main four cement companies in France was assembled (9,118 workers, 122,124 person-years of follow-up between 1990 and 2005). A common job titles classification was used to analyse occupational risk factors. We conducted a standardized mortality ratio analysis based on age, gender and calendar-period-specific national mortality rates and explored the combined effect of job titles and duration through an internal Cox regression analysis. RESULTS: The number of deaths during the follow-up period was 430 (4.7%). Malignant neoplasm was the cause of 48.1% of deaths. Overall, a deficit in all-causes mortality (standardized mortality ratio (SMR): 0.68, 95% confidence interval (CI) 0.61-0.74) and in cancer mortality (SMR: 0.80, CI 0.69-0.92) was observed. Working in the quarry, yard and shipping sectors was associated with a 50% higher all-causes mortality risk in comparison with the administrative sector. CONCLUSIONS: This cohort study does not support previous observations that cement workers are at higher risk of cancer mortality than the general population. The length of follow-up should be increased, and specific exposures deserve analysis.

[Obstructive sleep apnea syndrome]. / Syndrome d'apnées obstructives du sommeil.

Obstructive sleep apnea syndrome is a common disorder associated with potentially severe complications. Polysomnography is the gold standard diagnostic tool, while CPAP ventilation is recognized as the most efficient therapy. The numerous symptoms, even though little specific, should be rapidly detected to screen for the syndrome and transfer the patient to an adequate healthcare facility. The severity of the condition depends on the complications it causes.

Relevance of 5 different imaging signs in the evaluation of carotid artery invasion by cervical lymphadenopathy in head and neck squamous cell carcinoma.

OBJECTIVE: The aim of this retrospective study was to determine the relevance of 5 different imaging signs in the evaluation of carotid artery invasion. SUBJECTS AND METHODS: Between September 2001 and September 2008, 22 patients (20 men and 2 women) presented with lymph node metastasis of a head and neck squamous cell carcinoma that invaded the carotid artery. The patients received either carotid artery dissection (CAD, group 1 [n = 17]) or carotid resection (group 2 [n = 5]). Preoperative images using CT (n = 18) and/or MRI (n = 14) were analyzed. RESULTS: In 1 of 17 cases in group 1 and in 5 of 5 cases in group 2, encasement of more than 180 degrees of the artery was present (P < .05). Segmental obliteration of the fat between the lymph node and the carotid artery was noted in 7 of 17 cases in group 1 and for all cases in group 2 (P < .05). Deformation of the carotid artery was reported in no cases in group 1 and in all cases in group 2 (P < .05). CONCLUSION: The combination of deformation of the carotid artery, encasement of more than 180 degrees of the carotid perimeter, and segmental obliteration of the fat between the adenopathy and the carotid artery was highly predictive of massive invasion of the carotid artery, which would require a resection en bloc. In comparison, the isolated existence of encasement of more than 180 degrees or segmental obliteration of fat could not strictly indicate massive invasion of the carotid artery; thus, CAD could be planned.

Comparison of LigaSure vessel sealing system, harmonic scalpel, and conventional hemostasis in total thyroidectomy.

OBJECTIVE: The aim of the study was to compare the efficiency, safety, and cost of the different methods of hemostasis (conventional hemostasis versus LigaSure vessel sealing system [LVSS] versus harmonic scalpel) currently available for thyroid surgery. STUDY DESIGN: Randomized, controlled trial. SETTING: The study was conducted from September 2007 to December 2008 in a university hospital. PATIENTS AND METHODS: Sixty patients (48 females and 12 males) underwent a total thyroidectomy for multinodular goiter. They were randomly assigned into three groups: group one (n = 20), conventional hemostasis; group two (n = 20), LigaSure; and group three (n = 20), harmonic scalpel. RESULTS: For group three, the mean operative time was 37 minutes shorter than group one (P < 0.001) and eight minutes shorter than group two (P = 0.04). The complications rate was similar among the three groups. The mean postoperative paracetamol consummation in group one was 1.4 g greater than in group two (P = 0.016) and 1.3 g greater than in group three (P = 0.02). The overall average operative cost was 11 and 85 dollars cheaper for groups two and three than for group one, respectively (P < 0.001). CONCLUSION: Total thyroidectomy using the harmonic scalpel was the fastest procedure because it was bloodless, and hemostasis and sectioning were controlled with a single instrument; it was, therefore, the most inexpensive procedure because of the reduction of operative time and staff cost. The operative safety was similar for all three procedures. In our series, the harmonic scalpel and the LVSS caused less pain than the conventional hemostasis.

Ultrasonic partial glossectomy.

INTRODUCTION: Partial glossectomy is the main treatment for tongue carcinoma. The resection of the tongue, which is a very vascularised tissue, requires a good hemostasis. The advantage of the harmonic scalpel is in combining sectioning and hemostasis in one single instrument, allowing a bloodless dissection of soft tissue. The aim of this prospective study was to evaluate the benefits and risks when using a harmonic scalpel in partial glossectomy. SUBJECTS AND METHODS: In this prospective study conducted in a university hospital from march 2004 to December 2008, eighteen consecutive patients underwent a partial glossectomy with the use of harmonic scalpel. Results were compared with previous surgical procedures performed between September 2000 and February 2004 by monopolar hemostasis by our team (n = 12) when the harmonic scalpel was not available. RESULTS: All 18 patients underwent partial glossectomy with the harmonic scalpel as the only instrument of section and hemostasis. The median blood loss was of 0 mL. The median operative time was 29 minutes (16 minutes less than partial glossectomies performed with conventional hemostasis. P < .001). No operative complications occurred. Two post-operative bleedings (5 days and 7 days after the glossectomy) occurred necessitating a new surgery to ligate the lingual artery. The margins of the resection were acceptable and no recurrence appeared. CONCLUSION: The harmonic scalpel makes it fast and easy to perform a partial glossectomy with no bleeding. Ligation of the lingual artery (when it is visualized during the dissection) should be performed because of the frequency (more than 10% in our series) and because of the potential gravity of a lingual post-operative bleeding.

Carotid artery resection and reconstruction with superficial femoral artery transplantation: a case report.

INTRODUCTION: Managing advanced head and neck cancer is often a difficult task, particularly when massive invasion of the carotid artery is present. However, en bloc resection can be a curative procedure, and reconstruction of the carotid artery limits the risk for stroke. The aim of this study was to describe the interest, indication, potential risks, and methods by which we carried out resections as well as reconstructions of the carotid artery using superficial femoral artery transplantation. SUBJECTS AND METHODS: We presented one case of en bloc resection of the carotid artery with reconstruction with superficial femoral artery transplantation. RESULTS: Postoperative care was uneventful. The patient did not suffer from neurological deficiency. After three years of follow-up, the patient survived without any cancer recurrence. CONCLUSION: The occurrence of massive cancer invasion into the carotid artery should not be a contraindication for surgery. En bloc resection of the carotid artery with revascularization using the superficial femoral artery allows for appropriate control of the cancer, and carries an acceptable level of neurological risk.

Vocal tract area function for vowels using three-dimensional magnetic resonance imaging. A preliminary study.

OBJECTIVE: To assess whether magnetic resonance imaging (MRI) allows the vocal tract (VT) area function to be determined for a normal male speaker. METHOD: VT shapes were acquired using MRI during sustained production of French points vowels: /i/, /a/, /u/. Cross-sectional areas were measured from a series of planes spaced at intervals of 1 cm along the length of the VT and were used as input in a previously described VT model to simulate the vowels. The first three formant frequencies, F1, F2, and F3, computed from the MRI-measured VT model were compared with subject's natural formant frequencies. RESULTS: Including piriform sinuses, calculated formants differed from measured formants F1, F2, and F3, respectively, for /i/ by -3.5%, +7.7%, and +27.5%; for /a/ by +11% +19.5%, and -4.3%; and for /u/ by +.9%, +23.4%, and +9.6%. Excluding piriform sinuses, calculated formants differed from measured formants F1, F2, and F3, respectively, for /i/ by -3.5%, +12%, and +28%, and for /u/ by +10.1%, +26.8%, and +13.7% The piriform sinuses were not visualized for /a/ on MRI. CONCLUSIONS: MRI is a noninvasive technique that allows VT imaging and determination of VT area function for a normal male speaker. Several possible sources of discrepancies are as follows: variability of the articulation, difficulties in assessment of VT wall boundaries, role of the piriform sinuses, and VT length.

Follicular dendritic cell sarcoma of the tonsil: a case report.

Follicular dendritic cell sarcomas of the tonsil are very rare tumors. Only 10 cases have been published in the English-language medical literature. We present an additional case that occurred in a 27-year-old woman. She presented with a tumor of the right tonsil. Histological sections of tonsillar biopsies and tonsillectomy suggested that this tumor was a nerve sheath tumor or a malignant melanoma. Histological examination and immunohistochemical study were reviewed. The final diagnosis was follicular dendritic cell sarcoma. She underwent a transoral resection of the right oropharynx with ipsilateral selective neck dissection and postoperative irradiation. We emphasize the difficulties in diagnosing this type of tumor. The use of monoclonal specific markers is required to avoid misdiagnosis. We discuss therapeutic methods for this rare tumor for which optimal treatment has not yet been defined.

Early-stage glottic cancer: oncological results and margins in laser cordectomy.

OBJECTIVES: To assess local control of early-stage glottic cancer by laser cordectomy in comparison with previously published external partial laryngectomy series and to determine the relevance of histological margins in glottic cancers excised with laser cordectomy. DESIGN: Retrospective review of laser cordectomy for carcinoma in situ (Tis) and stage T1 glottic cancer from January 1991 to January 2004. SETTING: University hospital. PATIENTS: Fifty-two patients with Tis or T1 glottic cancer. INTERVENTION: Endoscopic laser cordectomy, classified using the system proposed by the European Laryngeal Society Working Committee. MAIN OUTCOME MEASURES: Local control after initial surgery and after salvage compared with a published historical control group, according to the type of cordectomy performed and the histological margins of the removed specimen. RESULTS: Sixteen patients with Tis, 30 with T1a tumors, and 6 with T1b tumors were followed up for an average of 38 months. Type I cordectomy was the most common procedure used to treat Tis, and type II and type III were the most common for treating T1a and T1b tumors. Of 6 recurrences, 4 were treated with laser cordectomy and 2 were treated with external partial laryngectomy. The rate of laryngeal preservation was 100%. There were 3 recurrences despite histologically clear margins. Three (17%) of 18 patients with suspicious margins developed recurrences. The rate of local control with single intervention (46 [89%] of 52) was lower than with partial external laryngectomy. However, 46 (89%) of 52 patients ultimately had less tissue removed by laser than would have been removed by external partial laryngectomy. CONCLUSIONS: Laser cordectomy provides excellent local control and laryngeal preservation. Close follow-up of patients with positive or suspicious margins is an alternative to further routine treatment.

Dilatation for assisted ventilation-induced laryngotracheal stenosis.

OBJECTIVE: To assess the long-term results of dilatation and our experience with dilatation for assisted ventilation-induced laryngotracheal stenosis. DESIGN: A retrospective study of 32 patients primarily treated with dilatation for assisted ventilation-induced laryngotracheal stenosis between 1977 and 2002. SETTING: A tertiary care center and university teaching hospital. PATIENTS: There were 19 men and 13 women aged 15 to 76 years. The stenosis was cicatricial with some inflammatory process in 27 patients and completely mature in 5 patients. The stenosis involved the cricoid and the trachea in four patients. In 28 patients, the stenosis involved only the trachea. METHODS: Dilatation was performed with serially sized rigid bronchoscopes. Endoscopic laser vaporization was never performed in this series. Six patients were treated with only one dilatation. The 26 remaining patients were treated with successively 2 to 10 dilatations (mean, 3.3 dilatations). The dilatation success rate was analyzed using the Kaplan-Meier method. RESULTS: Median duration of follow-up was 1.8 years. Mortality rate was 9.4%. The overall failure rate was 71.8%. Twenty patients presented with recurrent stenosis. The treatment of recurrent stenosis consisted of tracheal resection with end-to-end anastomosis (11 patients, 55%), cricotracheal anastomosis (5 patients, 25%), tracheal endoprosthesis (2 patients, 10%), and tracheotomy (1 patient, 5%). All patients who underwent tracheal or cricotracheal anastomosis were successfully treated. None of the variables under analysis (sex, age, medical history, cause for intubation, intubation type and duration, delay from initial injury, degree of stenosis, length of trachea involved, number of dilatations) were statistically related to the incidence of complications and the success rate of dilatations. CONCLUSIONS: We do not recommend dilatation technique as the sole treatment for assisted ventilation-induced laryngotracheal stenosis. This technique is helpful in case of emergency to restore an airway and useful for the assessment of stenosis.

Variability of electroglottographic glottal closed quotients: necessity of standardization to obtain normative values.

OBJECTIVE: To demonstrate the variability of electroglottographic measurements of the glottal closed quotient (GCQ) in normal subjects by the calculation method used, fundamental frequency, and intensity. DESIGN: Prospective study. SETTING: Tertiary university-based referral center. SUBJECTS: Twenty healthy male volunteers without laryngeal disorder. Three successive sustained productions of the vowel /a/ were performed by each subject. Electroglottographic recordings of GCQ were obtained using the criterion level method, which defines an approximate duration of glottal closure and opening. Glottal closed quotient values were calculated based on criterion levels ranging from 10% to 40%. MAIN OUTCOME MEASURES: The extent of correlation between GCQ variation and the mean fundamental frequency and intensity. RESULTS: As the criterion level increased, a decrease in the mean GCQ was recorded, which was significant with a 10% criterion level increase, up to a critical level of 25%. A significant positive correlation was found between GCQ and the variables of fundamental frequency and intensity. CONCLUSIONS: This study demonstrated significant effects of the criterion level used, fundamental frequency, and intensity in the determination of normative values of GCQ. Normative values can only be assessed through the standardization of one criterion level reached by consensus.