Real-time magnetic resonance imaging: mechanics of oral and facial function.

We report a summary of developmental work to explore, develop, and establish clinical applications of real-time magnetic resonance imaging (rtMRI) with a temporal resolution of 70 frames/second in oral and maxillofacial surgery (OMFS). Real-time MRI can contribute to procedure planning, diagnostics, rehabilitation, monitoring, and patient education. At present, conventional MRI is used extensively in the diagnosis, staging, and follow up of head and neck cancer patients, with scanning durations typically of several minutes and temporal resolution of up to 0.5 frames/second. The potential for rtMRI, where function can be assessed, could go far beyond the established clinical application of conventional MRI. Preliminary prototyping is a first stage in the establishment of rtMRI in OMFS. We follow best-practice approaches in co-creation across multiple disciplines, an indispensable aspect in the development of new methodologies and diagnostic tools.

Was it Good for You? Gender Differences in Motives and Emotional Outcomes Following Casual Sex.

Casual sex, also referred to as a hookup, has been associated with a range of negative emotional outcomes for women, including regret, anxiety, depression and social stigma. However, it has been argued that it is the nature of the sexual motivation, not gender that influences the emotional outcome. This study was designed to ascertain what motivates people to have casual sex, what emotional outcomes follow casual sex and whether there are gender differences among these variables. Seven hundred and one participants (47% men and 52.8% women) completed a 44-item online survey. Gender differences were found for both sexual motivations and emotional outcomes of casual sex, with women generally having more negative emotional outcomes than men. Additionally, a principal components analysis uncovered four reliable principal motivations underlying engagement in casual sex, and three principal emotional outcomes of casual sex. Predictors of negative emotional outcomes included being motivated to regulate negative emotions and to achieve positive emotions. No predictors (apart from being a man) were found for a positive emotional outcome. While the stigma surrounding female sexual agency is diminishing, results generally support the presence of a sexual double-standard which encourages male promiscuity but dissuades female sexual autonomy.

Polyoxovanadates as new P-glycoprotein inhibitors: insights into the mechanism of inhibition.

A promising strategy to overcome multidrug resistance is the use of inhibitors of ABC drug transporters. For this reason, we evaluated the polyoxovanadates (POVs) [V10 O28 ]6- (V10 ), [H6 V14 O38 (PO4 )]5- (V14 ), [V15 O36 Cl]6- (V15 ) and [V18 O42 I]7- (V18 ) as inhibitors of three major multidrug resistance-linked ABC transporters: P-glycoprotein (P-gp), ABCG2 and MRP1. All of the POVs selectively inhibited P-gp. V10 and V18 were the two most promising compounds, with IC50 values of transport inhibition of 25.4 and 22.7 µm, respectively. Both compounds inhibited P-gp ATPase activity, with the same IC50 value of 1.26 µm. V10 and V18 triggered different conformational changes in the P-gp protein with time-dependent inhibition, which was confirmed using the synthesized salt of V10 with rhodamine B, RhoB-V10 . The hydrophilic nature of POVs supports the hypothesis that these compounds target an unusual ligand-binding site, opening new possibilities in the development of potent modulators of ABC transporters.

Case Report 18F-FDG PET/CT of Pseudomyogenic Hemangioendothelioma.

Hemangioendotheliomas are a heterogeneous group of vascular neoplasm that may affect the liver, bone, and soft tissues. Among its variants, pseudomyogenic hemangioendothelioma is rarely encountered. Pseudomyogenic hemangioendothelioma is usually characterized by multiple soft tissue lesions, with occasional bone lesions. Fewer than 20 cases with exclusive involvement of bone structures have been reported. We describe a case of pseudomyogenic hemangioendothelioma involving multiple bony structures but without soft tissue involvement in a 7-year-old girl, imaged with F-FDG PET/CT at diagnosis and during treatment with mammalian target of rapamycin inhibitors.

In Vitro Assays to Monitor the Enzymatic Activities of zDHHC Protein Acyltransferases.

A family of zDHHC protein acyltransferase (PAT) enzymes catalyze the S-palmitoylation of target proteins via a two-step mechanism. The first step involves transfer of palmitate from the palmitoyl-CoA donor to the active site cysteine of the zDHHC PAT enzyme, releasing reduced CoA (CoASH). In the second step, the palmitoyl-PAT intermediate thioester reacts with a cysteine side chain within the target substrate to produce the palmitoylated substrate product or, in the absence of a protein substrate, the palmitoyl-PAT intermediate thioester is hydrolyzed and releases palmitate. Formation and resolution of the palmitoyl-PAT intermediate complex (autopalmitoylation) is measured using a coupled enzyme system that monitors the production of CoASH via reduction of NAD+ by the α-ketoglutarate dehydrogenase complex. This assay can be used to isolate and characterize modulators of autopalmitoylation and is scalable to high-throughput screening (HTS). A second fluorescence-based assay is described that monitors the hydrolysis of the palmitoyl-PAT thioester linked intermediate by thin-layer chromatography using a palmitoyl-CoA analog, BODIPY®-C12:0-CoA, as a substrate. These two assays provide a methodology to quantify the first enzymatic step of the two-step zDHHC PAT reaction.

The ammonium transporter AmtB and the PII signal transduction protein GlnZ are required to inhibit DraG in Azospirillum brasilense.

The ammonium-dependent posttranslational regulation of nitrogenase activity in Azospirillum brasilense requires dinitrogenase reductase ADP-ribosyl transferase (DraT) and dinitrogenase reductase ADP-glycohydrolase (DraG). These enzymes are reciprocally regulated by interaction with the PII proteins, GlnB and GlnZ. In this study, purified ADP-ribosylated Fe-protein was used as substrate to study the mechanism involved in the regulation of A. brasilense DraG in vitro. The data show that DraG is partially inhibited by GlnZ and that DraG inhibition is further enhanced by the simultaneous presence of GlnZ and AmtB. These results are the first to demonstrate experimentally that DraG inactivation requires the formation of a ternary DraG-GlnZ-AmtB complex in vitro. Previous structural data have revealed that when the DraG-GlnZ complex associates with AmtB, the flexible T-loops of the trimeric GlnZ bind to AmtB and become rigid; these molecular events stabilize the DraG-GlnZ complex, resulting in DraG inactivation. To determine whether restraining the flexibility of the GlnZ T-loops is a limiting factor in DraG inhibition, we used a GlnZ variant that carries a partial deletion of the T-loop (GlnZΔ42-54). However, although the GlnZΔ42-54 variant was more effective in inhibiting DraG in vitro, it bound to DraG with a slightly lower affinity than does wild-type GlnZ and was not competent to completely inhibit DraG activity either in vitro or in vivo. We, therefore, conclude that the formation of a ternary complex between DraG-GlnZ-AmtB is necessary for the inactivation of DraG.

Race-specific molecular alterations correlate with differential outcomes for black and white endometrioid endometrial cancer patients.

BACKGROUND: The objective of this study was to identify molecular alterations associated with disease outcomes for white and black patients with endometrioid endometrial cancer (EEC). METHODS: EEC samples from black (n = 17) and white patients (n = 13) were analyzed by proteomics (liquid chromatography-tandem mass spectrometry) and transcriptomics (RNA-seq). Coordinate alterations were validated with RNA-seq data from black (n = 49) and white patients (n = 216). Concordantly altered candidates were further tested for associations with race-specific progression-free survival (PFS) in black (n = 64) or white patients (n = 267) via univariate and multivariate Cox regression modeling and log-rank testing. RESULTS: Discovery analyses revealed significantly altered candidate proteins and transcripts between black and white patients, suggesting modulation of tumor cell viability in black patients and cell death signaling in black and white patients. Eighty-nine candidates were validated as altered between these patient cohorts, and a subset significantly correlated with differential PFS. White-specific PFS candidates included serpin family A member 4 (SERPINA4; hazard ratio [HR], 0.89; Wald P value = .02), integrin subunit α3 (ITGA3; HR, 0.76; P = .03), and Bet1 Golgi vesicular membrane trafficking protein like (BET1L; HR, 0.48; P = .04). Black-specific PFS candidates included family with sequence similarity 228 member B (FAM228B; HR, 0.13; P = .001) and HEAT repeat containing 6 (HEATR6; HR, 4.94; P = .047). Several candidates were also associated with overall survival (SERPINA4 and ITGA3) as well as PFS independent of disease stage, grade and myometrial invasion (SERPINA4, BET1L and FAM228B). CONCLUSIONS: This study has identified and validated molecular alterations in tumors from black and white EEC patients, including candidates significantly associated with altered disease outcomes within these patient cohorts. Cancer 2017;123:4004-12. © 2017 American Cancer Society.

Form and Size Matter: Increased Risk of Thrombosis in Microvessels with Surgically Created Endothelial Lesions.

Background Atherosclerosis is a known risk factor for flap loss in microsurgery. Several microsurgical techniques, like plaque removal, have been proposed for atherosclerotic vessels, but these techniques often induce intimal injuries. The aim of this study was to investigate the impact of various endothelial defects on the risk of thrombosis in a rat acute intimal injury model. Methods Endothelial defects of various forms and sizes were created in the abdominal aorta of 30 male Wistar rats following a strict protocol. Defect sizes were measured and classified as round, horizontal, or vertical based on their configuration. An hour after reestablishing the blood flow, the abdominal aorta was harvested and the operation site was assessed for signs of thrombosis clinically and using light microscopy. Univariate and multiple linear regression analysis were performed to identify possible influencing factors on thrombosis. Results The mean defect size was 2.65 ± 1.19 mm2. Intimal lesions were classified as round in 36.7%, horizontal in 33.3%, and vertical in 30% of specimens. Thrombus formation was detected in 46.7% clinically and in 50% histologically. Univariate regression analysis revealed that defect size (p = 0.048) and vertical form (p = 0.017) were significantly associated with thrombus formation. Multiple regression analysis corroborated vertical defects as a risk factor for thrombosis (p = 0.03). Conclusion Endothelial injuries are associated with a high risk of thrombosis with highest risks associated with vertical defects. Arteries should be carefully examined for intimal defects before microvascular anastomosis, especially in the atherosclerotic patient.

Indocyanine green videoangiography-assisted prediction of flap necrosis in the rat epigastric flap using the flow® 800 tool.

BACKGROUND: The decision to re-operate on a potentially ischemic free flap remains challenging. Indocyanine green videoangiography (ICG) with the FLOW® 800 tool is a method which allows an immediate qualitative conclusion about the patency of an anastomosis. Is it also able to predict the outcome of potentially compromised vascular free flaps? MATERIALS AND METHODS: An epigastric flap was raised and repositioned in 79 rats. Intraoperative fluorescence angiography was performed using ICG videoangiography and the FLOW® 800 tool was applied. Six regions of interest were positioned systematically over the flap, changes of the ICG fluorescence were color coded with respect to time and 474 measurements were performed. The flap was clinically monitored for one week and the resulting necrotic areas were correlated with the ICG/FLOW® 800 results. RESULTS: Mean intensity of clinically vital areas was 83.39 ± 50.96 arbitrary units (AU) and 37.33 ± 15.14 AU in necrotic areas. The receiver operating characteristic curve and Youden-Index analysis revealed that the optimal cutoff for the maximal intensity of ICG after FLOW® 800 analysis was ≤ 61.733 for the prediction of flap necrosis and > 61.733 for the prediction of flap survival (P < 0.0001; 95% CI = 0.85-0.91; Youden-Index: 0.67). The maximal intensity of ICG angiography had a specificity of 96.1% and sensitivity of 71.4%. The positive predictive value was 97.46% and the corresponding negative predictive value was 61.34%. CONCLUSION: This demonstrates the potential additional value of ICG videoangiography including FLOW® 800 analyses in the postoperative monitoring of transplanted flaps. © 2016 Wiley Periodicals, Inc. Microsurgery 37:235-242, 2017.

Impact of different antithrombotics on the microcirculation and viability of perforator-based ischaemic skin flaps in a small animal model.

The effects of antithrombotic drugs on random and free flap survival have been investigated in the past, but the experimental and clinical results are not in agreement. A perforator-based critical ischaemia model was used to evaluate the effects of different perioperatively administered pharmaceutical agents on tissue ischaemia and to assess the potential additional haemorheological or vasodilative effects of antithrombotics on flap microcirculation. Combined laser Doppler flowmetry and remission spectroscopy revealed an increase in certain microcirculation parameters in most groups in comparison with saline controls, and these changes correlated with flap survival. Clopidogrel and hirudin significantly improved the amount of viable flap tissue in comparison with controls, while unfractioned heparin had a negative effect on flap survival. Low molecular weight heparin, aspirin, pentoxifylline, and hydroxyethyl starch had no impact on the amount of viable flap tissue. A higher complication rate was observed in all experimental groups, but only clopidogrel had a negative impact on the flap viability. Our results add to the body of evidence supporting the conclusion that perioperative antithrombotic treatment improves flap survival. Clopidogrel and hirudin are effective pharmacological agents that significantly increased the viability of perforator-based skin flaps in rats, but at a higher risk of postoperative bleeding.

Bisphosphonate and Medication-Related Osteonecrosis of the Jaw: A Review.

For patients with malignant disease taking bisphosphonates and denosumab, the incidence of medication-related osteonecrosis of the jaw (MRONJ) is up to 15% in contrast to 0.01% in patients with osteoporosis. Clinical presentation of MRONJ extends from asymptomatic exposure of bone in 94% of patients to severe cases of mandibular fractures in a minority of 4.5%. The strongest risk factors for MRONJ are invasive dental procedures and dental infections. Advances in imaging provide more preoperation information compared with panoramic radiograph. Prevention strategies are the elimination of potential risk factors leading to invasive dental procedures and maintenance of good oral hygiene prior to the administration of antiresorptive agents. Management of MRONJ depends on the underlying disease, extent of the necrosis, and the presence of contributing therapy. Conservative therapies include topical anti-infective rinses and systemic antibiotic therapy. The most important part of surgical therapy is to remove the exposed and necrotic bone. Several options for defect closure are possible from local tissue flaps to microvascular free flap procedures. The development of MRONJ in conjunction with dental implants is a severe side effect and should be avoided if potentially harmful medication has already been administered.

Palmitoyl acyltransferase DHHC21 mediates endothelial dysfunction in systemic inflammatory response syndrome.

Endothelial dysfunction is a hallmark of systemic inflammatory response underlying multiple organ failure. Here we report a novel function of DHHC-containing palmitoyl acyltransferases (PATs) in mediating endothelial inflammation. Pharmacological inhibition of PATs attenuates barrier leakage and leucocyte adhesion induced by endothelial junction hyperpermeability and ICAM-1 expression during inflammation. Among 11 DHHCs detected in vascular endothelium, DHHC21 is required for barrier response. Mice with DHHC21 function deficiency (Zdhhc21dep/dep) exhibit marked resistance to injury, characterized by reduced plasma leakage, decreased leucocyte adhesion and ameliorated lung pathology, culminating in improved survival. Endothelial cells from Zdhhc21dep/dep display blunted barrier dysfunction and leucocyte adhesion, whereas leucocytes from these mice did not show altered adhesiveness. Furthermore, inflammation enhances PLCß1 palmitoylation and signalling activity, effects significantly reduced in Zdhhc21dep/dep and rescued by DHHC21 overexpression. Likewise, overexpression of wild-type, not mutant, PLCß1 augments barrier dysfunction. Altogether, these data suggest the involvement of DHHC21-mediated PLCß1 palmitoylation in endothelial inflammation.

Prevention of bisphosphonate-related osteonecrosis of the jaws in patients with prostate cancer treated with zoledronic acid - A prospective study over 6 years.

INTRODUCTION: To explore the preventive effect of a prophylactic oral and maxillofacial treatment to reduce bisphosphonate associated necrosis of the jaws (BRONJ) in metastatic prostate cancer (PC) patients treated with zoledronic acid (4.0 mg i.v./months). MATERIALS AND METHOD: 253 PC patients with bone metastases were prospectively randomized. All patients received baseline assessments including a dental panoramic tomogram. Group A was monitored and treated where deemed necessary by the patient's dentist and were re-evaluated once a year. In group B patients were monitored and treated where necessary by the authors at 12 week intervals. We compared the incidence rate per year (IR) and incidence proportion (IP) in both cohorts and assessed independent risk factors for BRONJ. RESULTS: Patients in group A were evaluated 3.2 (range 2-4) vs. 6.8 times (range 4-24) in group B. A significantly higher proportion of dental extractions was performed in group B vs. A (26.7% vs. 22.7%, p = 0.006). A BRONJ was detected with an IP of 23.3% vs. 2.2% in group A vs. B, revealing a 2.59 fold higher relative risk for group A (p = 0.01, 95% CI 0.01-0.56). The IR in group A was 0.073 cases/year while the IR in group B was significantly decreased by 82% to 0.0131 (p < 0.001). Extraction therapy was the only independent risk factor for BRONJ (p < 0.0001; 95% CI 21.22-189.06). CONCLUSIONS: Preventive oral and maxillofacial treatment before bisphosphonate application combined with 3-monthly dental follow-ups significantly reduces the occurrence and risk of BRONJ in PC patients. Therefore this approach should be implemented in the specific treatment algorithms.

The exceptionally high reactivity of Cys 621 is critical for electrophilic activation of the sensory nerve ion channel TRPA1.

Activation of the sensory nerve ion channel TRPA1 by electrophiles is the key mechanism that initiates nociceptive signaling, and leads to defensive reflexes and avoidance behaviors, during oxidative stress in mammals. TRPA1 is rapidly activated by subtoxic levels of electrophiles, but it is unclear how TRPA1 outcompetes cellular antioxidants that protect cytosolic proteins from electrophiles. Here, using physiologically relevant exposures, we demonstrate that electrophiles react with cysteine residues on mammalian TRPA1 at rates that exceed the reactivity of typical cysteines by 6,000-fold and that also exceed the reactivity of antioxidant enzymes. We show that TRPA1 possesses a complex reactive cysteine profile in which C621 is necessary for electrophile-induced binding and activation. Modeling of deprotonation energies suggests that K620 contributes to C621 reactivity and mutation of K620 alone greatly reduces the effect of electrophiles on TRPA1. Nevertheless, binding of electrophiles to C621 is not sufficient for activation, which also depends on the function of another reactive cysteine (C665). Together, our results demonstrate that TRPA1 acts as an effective electrophilic sensor because of the exceptionally high reactivity of C621.

Identification of Protein Palmitoylation Inhibitors from a Scaffold Ranking Library.

The addition of palmitoyl moieties to proteins regulates their membrane targeting, subcellular localization, and stability. Dysregulation of the enzymes which catalyzed the palmitoyl addition and/or the substrates of these enzymes have been linked to cancer, cardiovascular, and neurological disorders, implying these enzymes and substrates are valid targets for pharmaceutical intervention. However, current chemical modulators of zDHHC PAT enzymes lack specificity and affinity, underscoring the need for screening campaigns to identify new specific, high affinity modulators. This report describes a mixture based screening approach to identify inhibitors of Erf2 activity. Erf2 is the Saccharomyces cerevisiae PAT responsible for catalyzing the palmitoylation of Ras2, an ortholog of the human Ras oncogene proteins. A chemical library developed by the Torrey Pines Institute for Molecular Studies consists of more than 30 million compounds designed around 68 molecular scaffolds that are systematically arranged into positional scanning and scaffold ranking formats. We have used this approach to identify and characterize several scaffold backbones and R-groups that reduce or eliminate the activity of Erf2 in vitro. Here, we present the analysis of one of the scaffold backbones, bis-cyclic piperazine. We identified compounds that inhibited Erf2 auto-palmitoylation activity using a fluorescence-based, coupled assay in a high throughput screening (HTS) format and validated the hits utilizing an orthogonal gel-based assay. Finally, we examined the effects of the compounds on cell growth in a yeast cell-based assay. Based on our results, we have identified specific, high affinity palmitoyl transferase inhibitors that will serve as a foundation for future compound design.

The role of mylohyoid flap in the treatment of bisphosphonate-related osteonecrosis of the jaws.

INTRODUCTION: Surgical treatment of bisphosphonate-related osteonecrosis of the jaws (BRONJ) combines excision of adequate damaged bone and watertight coverage by appropriate vascularized tissue. Local tissues are preferred when possible. This study compares local mucoperiosteal flaps with mylohyoid flaps with special emphasis on their influence on wound healing. MATERIAL AND METHODS: A total of 195 patients with BRONJ in the mandible were included in this prospective study. The control group (n = 169) were treated with a mucoperiosteal flap, whereas patients of the study group (n = 26) received a mylohyoid flap. RESULTS: Recurrence of BRONJ was significantly reduced (p = 0.023) as was extent of necrosis (p = 0.001) in patients with mylohyoid flaps. DISCUSSION: This study demonstrates the importance of a sufficient mucosal coverage in surgical treatment of BRONJ. The mylohyoid flap provides an additional tissue coverage, which seems to account for the significantly reduced rate of disease recurrence. CONCLUSION: The vascularized mylohyoid flap is an important tool in the complex and challenging surgical care of BRONJ.