Tetrahydrobiopterin and alkylglycerol monooxygenase substantially alter the murine macrophage lipidome.

Tetrahydrobiopterin is a cofactor synthesized from GTP with well-known roles in enzymatic nitric oxide synthesis and aromatic amino acid hydroxylation. It is used to treat mild forms of phenylketonuria. Less is known about the role of tetrahydrobiopterin in lipid metabolism, although it is essential for irreversible ether lipid cleavage by alkylglycerol monooxygenase. Here we found intracellular alkylglycerol monooxygenase activity to be an important regulator of alkylglycerol metabolism in intact murine RAW264.7 macrophage-like cells. Alkylglycerol monooxygenase was expressed and active also in primary mouse bone marrow-derived monocytes and "alternatively activated" M2 macrophages obtained by interleukin 4 treatment, but almost missing in M1 macrophages obtained by IFN-γ and lipopolysaccharide treatment. The cellular lipidome of RAW264.7 was markedly changed in a parallel way by modulation of alkylglycerol monooxygenase expression and of tetrahydrobiopterin biosynthesis affecting not only various ether lipid species upstream of alkylglycerol monooxygenase but also other more complex lipids including glycosylated ceramides and cardiolipins, which have no direct connection to ether lipid pathways. Alkylglycerol monooxygenase activity manipulation modulated the IFN-γ/lipopolysaccharide-induced expression of inducible nitric oxide synthase, interleukin-1ß, and interleukin 1 receptor antagonist but not transforming growth factor ß1, suggesting that alkylglycerol monooxygenase activity affects IFN-γ/lipopolysaccharide signaling. Our results demonstrate a central role of tetrahydrobiopterin and alkylglycerol monooxygenase in ether lipid metabolism of murine macrophages and reveal that alteration of alkylglycerol monooxygenase activity has a profound impact on the lipidome also beyond the class of ether lipids.

Unbiased Metabolomic Investigation of Alzheimer's Disease Brain Points to Dysregulation of Mitochondrial Aspartate Metabolism.

Alzheimer's disease (AD) is the most common cause of adult dementia. Yet the complete set of molecular changes accompanying this inexorable, neurodegenerative disease remains elusive. Here we adopted an unbiased lipidomics and metabolomics approach to surveying frozen frontal cortex samples from clinically characterized AD patients (n = 21) and age-matched controls (n = 19), revealing marked molecular differences between them. Then, by means of metabolomic pathway analysis, we incorporated the novel molecular information into the known biochemical pathways and compared it with the results of a metabolomics meta-analysis of previously published AD research. We found six metabolic pathways of the central metabolism as well as glycerophospholipid metabolism predominantly altered in AD brains. Using targeted metabolomics approaches and MS imaging, we confirmed a marked dysregulation of mitochondrial aspartate metabolism. The altered metabolic pathways were further integrated with clinical data, showing various degrees of correlation with parameters of dementia and AD pathology. Our study highlights specific, altered biochemical pathways in the brains of individuals with AD compared with those of control subjects, emphasizing dysregulation of mitochondrial aspartate metabolism and supporting future venues of investigation.

Ion mobility-derived collision cross section as an additional measure for lipid fingerprinting and identification.

Despite recent advances in analytical and computational chemistry, lipid identification remains a significant challenge in lipidomics. Ion-mobility spectrometry provides an accurate measure of the molecules' rotationally averaged collision cross-section (CCS) in the gas phase and is thus related to ionic shape. Here, we investigate the use of CCS as a highly specific molecular descriptor for identifying lipids in biological samples. Using traveling wave ion mobility mass spectrometry (MS), we measured the CCS values of over 200 lipids within multiple chemical classes. CCS values derived from ion mobility were not affected by instrument settings or chromatographic conditions, and they were highly reproducible on instruments located in independent laboratories (interlaboratory RSD < 3% for 98% of molecules). CCS values were used as additional molecular descriptors to identify brain lipids using a variety of traditional lipidomic approaches. The addition of CCS improved the reproducibility of analysis in a liquid chromatography-MS workflow and maximized the separation of isobaric species and the signal-to-noise ratio in direct-MS analyses (e.g., "shotgun" lipidomics and MS imaging). These results indicate that adding CCS to databases and lipidomics workflows increases the specificity and selectivity of analysis, thus improving the confidence in lipid identification compared to traditional analytical approaches. The CCS/accurate-mass database described here is made publicly available.

Correlation Between Blood Loss and Patient-Related Factors in the Bilateral Parasymphyseal Osteotomy.

The aim of this study was to determine the correlation between pre- and postsurgical loss of blood and blood components among patients undergoing treatment of facial deformities by bilateral parasymphyseal osteotomy (BPsO).The pre- and postoperative values of blood components were determined in 30 facial deformity patients who underwent orthognathic surgery by hypotensive anesthesia. Correlations among the blood loss, sex, age, operation time, and reduced values of blood components were assessed by a correlation matrix. The mean blood loss and operation time were 437.5 (± 52.5) mL and 355.8 (± 209.42) minutes, respectively. Two patients included in this study had required blood transfusion. The mean reduced red blood cell (× 10/µL), hemoglobin (g/dL), and hematocrit (%) were -1.02, -2.98, and -9.18, respectively. There was no significant correlation between blood loss and other related factors (eg, age, operation time, and reduced blood components). All patients, however, showed significantly lower values of blood components after surgery. In conclusion, no significant factor was associated with blood loss and reduced blood components among patients undergoing BPsO. Furthermore, hypotensive anesthesia is a well-accepted method to reduce blood loss during orthognathic surgery.

Metabolic phenotyping reveals a lipid mediator response to ionizing radiation.

Exposure to ionizing radiation has dramatically increased in modern society, raising serious health concerns. The molecular response to ionizing radiation, however, is still not completely understood. Here, we screened mouse serum for metabolic alterations following an acute exposure to γ radiation using a multiplatform mass-spectrometry-based strategy. A global, molecular profiling revealed that mouse serum undergoes a series of significant molecular alterations following radiation exposure. We identified and quantified bioactive metabolites belonging to key biochemical pathways and low-abundance, oxygenated, polyunsaturated fatty acids (PUFAs) in the two groups of animals. Exposure to γ radiation induced a significant increase in the serum levels of ether phosphatidylcholines (PCs) while decreasing the levels of diacyl PCs carrying PUFAs. In exposed mice, levels of pro-inflammatory, oxygenated metabolites of arachidonic acid increased, whereas levels of anti-inflammatory metabolites of omega-3 PUFAs decreased. Our results indicate a specific serum lipidomic biosignature that could be utilized as an indicator of radiation exposure and as novel target for therapeutic intervention. Monitoring such a molecular response to radiation exposure might have implications not only for radiation pathology but also for countermeasures and personalized medicine.

Five Key Articles on Curriculum Development for Graduate Medical Educators.

Background Curriculum development is an essential domain for medical educators, yet specific training in this area is inconsistent. With competing demands for educators' time, a succinct resource for best practice is needed. Objective To create a curated list of the most essential articles on curriculum development to guide education scholars in graduate medical education. Methods We used a modified Delphi method, a systematic consensus strategy to increase content validity, to achieve consensus on the most essential curriculum development articles. We convened a panel of 8 experts from the United States in curricular development, with diverse career stages, institutions, gender, and specialty. We conducted a literature search across PubMed and Google Scholar with keywords, such as "curriculum development" and "curricular design," to identify relevant articles focusing on a general overview or approach to curriculum development. Articles were reviewed across 3 iterative Delphi rounds to narrow down those that should be included in a list of the most essential articles on curriculum development. Results Our literature search yielded 1708 articles, 90 of which were selected for full-text review, and 26 of which were identified as appropriate for the modified Delphi process. We had a 100% response rate for each Delphi round. The panelists narrowed the articles to a final list of 5 articles, with 4 focusing on the development of new curriculum and 1 on curriculum renewal. Conclusions We developed a curated list of 5 essential articles on curriculum development that is broadly applicable to graduate medical educators.

Development of a single mobile phase for LC-IM-MS-based discovery lipidomics and metabolic phenotyping: Application to methapyrilene hepatotoxicity in the rat.

The untargeted global profiling of endogenous metabolites and lipids has the potential to increase knowledge and understanding in many areas of biology. LC-MS/MS is a key technology for such analyses however, several different LC methodologies, using different mobile phase compositions, are required to cover the diversity in polarity and analyte structure encountered in biological samples. Most notably many lipid screening methods make use of isopropanol (IPA) as a major component of mobile phases employed for comprehensive lipidomic profiling. In order to increase laboratory efficiency, and minimize opportunities for errors, a suite of methods, based on a single acetonitrile (ACN)-aqueous buffer mobile phase combination, has been developed. This mobile phase can be used for hydrophobic interaction liquid chromatography on an amide stationary phase (for polar analytes), reversed-phase (RP) LC analysis on a C8 stationary phase (for moderately polar-non-polar compounds) and RPLC using a CSH phenyl-hexyl bonded column (for lipids). All of these sub 10 minute separations had good throughput and reproducibility with CV's of analyte response <25 % whilst eliminating the need for complex mobile phase preparation and the use of IPA as an organic modifier for lipidomics. Advantages of removing IPA and replacing it with the ACN-based method were a 58 % increase in peak capacity for lipids, with improved resolution for the di- and triglycerides and cholesterol esters compared to current methods. Compared to the IPA-containing solvent system the ACN-based mobile phase also resulted in a 61 % increase in lipid feature detection. The utility of this "universal" mobile phase approach was demonstrated by its application to a rat toxicology study investigating the consequences of methapyrilene administration through on the endogenous metabolite profiles of plasma and urine. Methapyrilene and its metabolites were also profiled in these samples.

Hypertensive Disorders of Pregnancy.

Hypertensive disorders in pregnancy are a leading cause of global maternal and fetal morbidity. The four hypertensive disorders of pregnancy include chronic hypertension, gestational hypertension, preeclampsia-eclampsia, and chronic hypertension with superimposed preeclampsia. A careful history, review of systems, physical examination, and laboratory analysis can help differentiate these disorders and quantify the severity of the disease, which holds important implications for disease management. This article reviews the different types of disorders of hypertension in pregnancy and how to diagnose and manage these patients, with special attention paid to any recent changes made to this management algorithm.

Leptomeningeal Carcinomatosis: A Rare Complication of Metastatic Gastric Cancer.

Leptomeningeal disease, also known as leptomeningeal carcinomatosis, occurs when cancer metastasizes to the meninges. This rare complication is associated with a poor prognosis. It is most commonly seen in patients with metastatic breast cancer, lung cancer, and melanoma. However, it is extremely rare in patients with metastatic gastric cancer. A 64-year-old female with poorly differentiated gastric adenocarcinoma metastatic to the peritoneum developed new neurological symptoms twelve months after initiating palliative chemotherapy. Her uptrending tumor markers, brain magnetic resonance imaging (MRI) findings, and lumbar puncture results were consistent with leptomeningeal disease. The patient was started on treatment with intrathecal methotrexate (IT MTX), which resulted in significant improvement in her neurological symptoms. Leptomeningeal disease in gastric cancer has limited treatment options due to poor blood-brain barrier penetration. IT MTX is a potentially effective treatment for patients with leptomeningeal disease from gastric cancer.

MolFind: a software package enabling HPLC/MS-based identification of unknown chemical structures.

In this paper, we present MolFind, a highly multithreaded pipeline type software package for use as an aid in identifying chemical structures in complex biofluids and mixtures. MolFind is specifically designed for high-performance liquid chromatography/mass spectrometry (HPLC/MS) data inputs typical of metabolomics studies where structure identification is the ultimate goal. MolFind enables compound identification by matching HPLC/MS-based experimental data obtained for an unknown compound with computationally derived HPLC/MS values for candidate compounds downloaded from chemical databases such as PubChem. The downloaded "bins" consist of all compounds matching the monoisotopic molecular weight of the unknown. The computational HPLC/MS values predicted include retention index (RI), ECOM(50) (energy required to fragment 50% of a selected precursor ion), drift time, and collision induced dissociation (CID) spectrum. RI, ECOM(50), and drift-time models are used for filtering compounds downloaded from PubChem. The remaining candidates are then ranked based on CID spectra matching. Current RI and ECOM(50) models allow for the removal of about 28% of compounds from PubChem bins. Our estimates suggest that this could be improved to as much as 87% with additional chemical structures included in the computational models. Quantitative structure property relationship-based modeling of drift times showed a better correlation with experimentally determined drift times than did Mobcal cross-sectional areas. In 23 of 35 example cases, filtering PubChem bins with RI and ECOM(50) predictive models resulted in improved ranking of the unknown compounds compared to previous studies using CID spectra matching alone. In 19 of 35 examples, the correct candidate was ranked within the top 20 compounds in bins containing an average of 1635 compounds.

Correlation of Ecom50 values between mass spectrometers: effect of collision cell radiofrequency voltage on calculated survival yield.

RATIONALE: The determination of the center-of-mass energy at which 50% of a precursor ion decomposes (Ecom(50)) during collision-induced dissociation (CID) is dependent on the chemical structure of the ion as well as the physical and electrical characteristics of the collision cell. The current study was designed to identify variables influencing Ecom(50) values measured on four different mass spectrometers. METHODS: Fifteen test compounds were protonated using + ve electrospray ionization and the resulting ions were fragmented across a range of collision energies by CID. Survival yield versus collision energy curves were then used to calculate Ecom(50) values for each of these [M+H](+) ions on four different mass spectrometers. In addition, the relative recovery of the [M+H](+) ions of eight compounds ranging in molecular weight from 46 to 854 Da were determined at collision cell radiofrequency (RF) voltages ranging from 0 to 600 V. RESULTS: Ecom(50) values determined on the four instruments were highly correlated (r(2) values ranged from 0.953 to 0.992). Although these overall correlations were high, we found different maximum ion recoveries depending on collision cell RF voltage. High-mass ions had greater recovery at higher collision cell RF voltages, whereas low-mass ions had greater recovery at lower collision cell RF voltages as well as a broader range of ion recoveries. CONCLUSIONS: Ecom(50) values measured on four different instruments correlated surprisingly well given the differences in electrical and physical characteristics of the collision cells. However, our results suggest caution when comparing Ecom(50) values or CID spectra between instruments without correcting for the effects of RF voltage on ion transfer efficiency.

Effects of patient- and operation-related factors on postoperative pain after orthognathic surgery.

PURPOSE: This study aimed to assess the association between patient- and operation-related factors and postoperative pain in patients undergoing intraoral vertical ramus osteotomy (IVRO) or IVRO + genioplasty (GeP) for the treatment of mandibular prognathism. MATERIALS AND METHODS: A visual analog scale (VAS) was used to evaluate postoperative pain for 2 days in 63 patients who underwent orthognathic surgery (42 IVRO and 21 IVRO + GeP). Correlations between VAS and patient age, sex, blood loss, operation time, and intraoperative reduction in blood parameters were assessed and compared between IVRO and IVRO + GeP procedures. RESULTS: Mean operation time and blood loss were 252.02 minutes and 99.64 mL in the IVRO group and 317.62 minutes and 187.86 mL in the IVRO + GeP group, respectively. Operation time, blood loss, and postoperative reduction in blood parameters were significantly greater in the IVRO + GeP group than in the IVRO group. Mean VAS scores on the first and second postoperative days were 3.02 and 1.33 in the IVRO group and 2.95 and 1.14 in the IVRO + GeP group. However, postoperative pain did not differ significantly between the IVRO and IVRO + GeP groups on the first or second postoperative day. CONCLUSIONS: Postoperative pain associated with orthognathic surgery was acceptable, controllable, and not different between IVRO and IVRO + GeP procedures.

Assessment of the related factors of blood loss and blood ingredients among patients under hypotensive anesthesia in orthognathic surgery.

OBJECTIVE: The objective of the study was to understand the factors associated with presurgical and postsurgical blood loss and blood ingredients among patients in the treatment of mandibular prognathism by intraoral vertical ramus osteotomy combined genioplasty. METHODS: Preoperative and postoperative values of blood loss and blood ingredients were collected from 30 mandibular prognathic patients who underwent orthognathic surgery. The linear regression models and correlation coefficients were used to identify factors with respect to patients' blood loss level and 3 types of blood ingredients (ie, red blood cells, hemoglobin, and hematocrit). RESULTS: The mean blood loss and operation time were 179.2 mL and 311.7 minutes, respectively. No blood transfusion was received by our patients. After adjusting for potential factors, the regression models showed that no significant factor was found to be associated with blood loss and reduce blood ingredients. Moreover, female patients were found to be more likely to have a low level of presurgical blood ingredients (ß = -0.293 to -3.551; P < 0.05), whereas female sex (ß = -1.606 to -4.008; P < 0.001), a high blood loss level (ß = -0.003 to -0.009; P < 0.05), and long operation time (ß = -0.005 to -0.018; P < 0.05) were associated with a low level of postsurgical blood ingredients (ie, hemoglobin and hematocrit). CONCLUSIONS: No significant factor was associated with blood loss and reduced blood ingredients among patients in orthognathic surgery with hypotenstive anesthesia. Improvements in anesthesia provided surgeons with more time to promote hemostasis during surgery. Hypotensive anesthesia was a well-accepted method to reduce blood loss during orthognathic surgery.

Changes in the transverse dimensions by vertical ramus osteotomy after mandibular prognathism correction.

OBJECTIVE: A harmonious face displays not only a good lateral profile but also a pleasant frontal appearance. The purpose of the current study was to evaluate the changes in the transverse dimensions by vertical ramus osteotomy (VRO) in the treatment of mandibular prognathism correction. METHODS: Twenty patients who underwent mandibular prognathism correction by VRO were included. Lateral and frontal cephalometric radiographs were obtained at the following stages: preoperative (T1), immediately after the surgery (T2), and completion of orthodontic treatment (T3). Three linear measurements (menton, intercondylion, and intergonial distances) and the ramus angle were compared from T1 to T3. RESULTS: A final mean menton setback of 12.2 mm and upward movement of 0.3 mm were noted. The intercondylion and intergonial distances significantly increased by 5.1 and 7.1 mm, respectively. Without significant difference, ramus angles decreased 1.7 degrees in the right side and 0.1 degrees in the left side. CONCLUSION: The surgical correction of mandibular prognathism using VRO led to an increase in the transverse dimensions.

Correlation between the change of gonial region and skeletal relapse after intraoral vertical ramus osteotomy for correction of mandibular prognathism.

BACKGROUND: The gonial region is coincided with harmonious face and masticatory function. The aims of the present study were to assess changes in the gonial region in patients who had mandibular setback surgery by intraoral vertical ramus osteotomy (IVRO) and to investigate the contributing factors in relation to skeletal relapse. METHODS: Twenty-one patients with mandibular prognathism were corrected by IVRO. Three cephalometric radiographs were collected from preoperative orthodontic treatment (T1), immediately after surgery (T2), and at 2-year postoperative follow-up (T3). Relapse was defined as forward movement of menton (Me) after the 2-year follow-up. Three angular (SN-Go angle, mandibular plane angle, and gonial angle) and 2 linear (horizontal-Me and vertical-Me) measurements were compared after immediate operation and at the 2-year follow-up. Spearman rank correlation and Student t tests were used for statistical analysis. RESULTS: The mean setback of the Me was 12.7 mm, and the mean relapse was 1.5 mm. The magnitude of setback was not significant for relapse. There were weak correlations between relapse and factors concerned with the gonial region (SN-Go angle, mandibular plane angle, and gonial angle). CONCLUSIONS: Surgical correction of mandibular prognathism using IVRO can lead to an increase in the angle changes of gonial region but not correlate to skeletal relapse in long-term follow-up.

The stability of intraoral vertical ramus osteotomy and factors related to skeletal relapse.

BACKGROUND: Intraoral vertical ramus osteotomy (IVRO) and sagittal split ramus osteotomy (SSRO) have been advocated as two major procedures for the correction of mandibular prognathism. However, only a few reports with at least a 2-year follow-up period describe the long-term stability especially of the IVRO method. This study aimed to identify factors contributing to skeletal relapse after a 2-year postoperative follow-up period. METHODS: A set of three standardized lateral cephalograms were obtained from each subject, taken preoperatively (T1), immediately postoperatively (T2), and 2 years postoperatively (T3). Relapse was defined as forward movement of the menton (Me) after a 2-year follow-up period. Two angular measurements (SNB and SN-occlusal plane angle) and five linear measurements (horizontal Me, vertical Me, overbite, anterior facial height, and mandibular length) were compared immediately after the operation and at the 2-year follow-up visit. RESULTS: The mean setback of the menton was 12.8 mm, and the mean relapse was 1.3 mm (10.2% = 1.3/12.8). The magnitude of the setback was not significantly accounted for in the relapse. There were weak correlations between the relapse and the concerned factors, namely, overbite, anterior facial height, mandibular length SNB, and SN-occlusal plane angle). CONCLUSION: The current study confirmed the stability of IVRO in the treatment of mandibular prognathism.

Radiology Education Among Emergency Medicine Residencies: A National Needs Assessment.

INTRODUCTION: Radiology training is an important component of emergency medicine (EM) education, but its delivery has been variable. Program directors have reported a lack of radiology skills in incoming interns. A needs assessment is a crucial first step toward improving radiology education among EM residencies. Our objective was to explore the current state of radiology education in EM residency programs. METHODS: This was a cross-sectional survey study of all Accreditation Council for Graduate Medical Education-accredited EM programs in the United States. Program leadership completed an online survey consisting of multiple choice, Likert scale, and free-response items. We calculated and reported descriptive statistics. RESULTS: Of eligible EM programs, 142/252 (56%) completed the survey including 105 postgraduate year (PGY) 1-3 and 36 PGY 1-4 programs. One respondent opted out of answering demographic questions. 23/141 (16%) were from the Western region, 29/141 (21%) were from the North Central region, 14/141 (10%) were from the South-Central region, 28/141 (20%) were from the Southeast region, and 47/141 (33%) were from the Northeast region. A total of 88/142 (62%) of responding programs did not have formal radiology instruction. Of the education that is provided, 127/142 (89%) provide it via didactics/lectures and 115/142 (81%) rely on instruction during clinical shifts. Only 51/142 (36%) provide asynchronous opportunities, and 23/142 (16%) have a dedicated radiology rotation. The majority of respondents reported spending 0-2 hours per month on radiology instruction (108/142; 76%); 95/141 (67%) reported that EM faculty "often" or "always" provide radiology instruction; 134/142 (95%), felt that it was "extremely" or "very important" for ED providers to be able to independently interpret radiograph results; and 129/142 (90.84%) either "sometimes" or "always" rely on their independent radiograph interpretations to make clinical decisions. The radiology studies identified as most important to be able to independently interpret were radiographs obtained for lines/tubes, chest radiographs, and radiographs obtained for musculoskeletal-related complaints. CONCLUSION: A minority of EM residency programs have formal instruction in radiology despite the majority of responding program leadership believing that these are important skills. The most important curricular areas were identified. These results may inform the development of formal radiology curricula in EM graduate medical education.