FOXOs modulate proteasome activity in human-induced pluripotent stem cells of Huntington's disease and their derived neural cells.

Although it has been speculated that proteasome dysfunction may contribute to the pathogenesis of Huntington's disease (HD), a devastating neurodegenerative disorder, how proteasome activity is regulated in HD affected stem cells and somatic cells remains largely unclear. To better understand the pathogenesis of HD, we analyzed proteasome activity and the expression of FOXO transcription factors in three wild-type (WT) and three HD induced-pluripotent stem cell (iPSC) lines. HD iPSCs exhibited elevated proteasome activity and higher levels of FOXO1 and FOXO4 proteins. Knockdown of FOXO4 but not FOXO1 expression decreased proteasome activity. Following neural differentiation, the HD-iPSC-derived neural progenitor cells (NPCs) demonstrated lower levels of proteasome activity and FOXO expressions than their WT counterparts. More importantly, overexpression of FOXO4 but not FOXO1 in HD NPCs dramatically enhanced proteasome activity. When HD NPCs were further differentiated into DARPP32-positive neurons, these HD neurons were more susceptible to death than WT neurons and formed Htt aggregates under the condition of oxidative stress. Similar to HD NPCs, HD-iPSC-derived neurons showed reduced proteasome activity and diminished FOXO4 expression compared to WT-iPSC-derived neurons. Furthermore, HD iPSCs had lower AKT activities than WT iPSCs, whereas the neurons derived from HD iPSC had higher AKT activities than their WT counterparts. Inhibiting AKT activity increased both FOXO4 level and proteasome activity, indicating a potential role of AKT in regulating FOXO levels. These data suggest that FOXOs modulate proteasome activity, and thus represents a potentially valuable therapeutic target for HD.

Temporal profiling of the coding and noncoding murine cytomegalovirus transcriptomes.

The global transcriptional program of murine cytomegalovirus (MCMV), involving coding, noncoding, and antisense transcription, remains unknown. Here we report an oligonucleotide custom microarray platform capable of measuring both coding and noncoding transcription on a genome-wide scale. By profiling MCMV wild-type and immediate-early mutant strains in fibroblasts, we found rapid activation of the transcriptome by 6.5 h postinfection, with absolute dependency on ie3, but not ie1 or ie2, for genomic programming of viral gene expression. Evidence is also presented to show, for the first time, genome-wide noncoding and bidirectional transcription at late stages of MCMV infection.

Fast DNA and protein microarray tests for the diagnosis of hepatitis C virus infection on a single platform.

Hepatitis C virus (HCV) is a major cause of chronic liver disease and liver cancer, and remains a large health care burden to the world. In this study we developed a DNA microarray test to detect HCV RNA and a protein microarray to detect human anti-HCV antibodies on a single platform. A main focus of this study was to evaluate possibilities to reduce the assay time, as a short time-to-result (TTR) is a prerequisite for a point-of-care test. Significantly reducing hybridisation and washing times did not impair the assay performance. This was confirmed first using artificial targets and subsequently using clinical samples from an HCV seroconversion panel derived from a HCV-infected patient. We were able to reduce the time required for the detection of human anti-HCV antibodies to only 14 min, achieving nanomolar sensitivity. The protein microarray exhibited an analytical sensitivity comparable to that of commercial systems. Similar results were obtained with the DNA microarray using a universal probe which covered all different HCV genotypes. It was possible to reduce the assay time after PCR from 150 min to 16 min without any loss of sensitivity. Taken together, these results constitute a significant step forward in the design of rapid, microarray-based diagnostics for human infectious disease, and show that the protein microarray is currently the most favourable candidate to fill this role.

Longitudinal assessment of lung cancer progression in the mouse using in vivo micro-CT imaging.

PURPOSE: Small animal micro-CT imaging is being used increasingly in preclinical biomedical research to provide phenotypic descriptions of genomic models. Most of this imaging is coincident with animal death and is used to show the extent of disease as an end point. Longitudinal imaging overcomes the limitation of single time-point imaging because it enables tracking of the natural history of disease and provides qualitative and, where possible, quantitative assessments of the effects of an intervention. The pulmonary system is affected by many disease conditions, such as lung cancer, chronic obstructive pulmonary disease, asthma, and granulomatous disorders. Noninvasive imaging can accurately assess the lung phenotype within the living animal, evaluating not only global lung measures, but also regional pathology. However, imaging the lung in the living animal is complicated by rapid respiratory motion, which leads to image based artifacts. Furthermore, no standard mouse lung imaging protocols exist for longitudinal assessment, with each group needing to develop their own systematic approach. METHODS: In this article, the authors present an outline for performing longitudinal breath-hold gated micro-CT imaging for the assessment of lung nodules in a mouse model of lung cancer. The authors describe modifications to the previously published intermittent isopressure breath-hold technique including a new animal preparation and anesthesia protocol, implementation of a ring artifact reduction, variable scanner geometry, and polynomial beam hardening correction. In addition, the authors describe a multitime-point data set registration and tumor labeling and tracking strategy. RESULTS: In vivo micro-CT data sets were acquired at months 2, 3, and 4 posturethane administration in cancer mice (n = 5) and simultaneously in control mice (n = 3). 137 unique lung nodules were identified from the cancer mice while no nodules were detected in the control mice. A total of 411 nodules were segmented and labeled over the three time-points. Lung nodule metrics including RECIST, Ortho, WHO, and 3D volume were determined and extracted. A tumor incidence rate of 30.44 +/- 1.93 SEM for n = 5 was found with identification of nodules as small as 0.11 mm (RECIST) and as large as 1.66 mm (RECIST). In addition, the tumor growth and doubling rate between months 2-3 and 3-4 were calculated. Here, the growth rate was slightly higher in the second period based on the 3D volume data (0.12 +/- 0.13 to 0.13 +/- 0.17 microl) but significantly less based on the linear diameter metrics [RECIST (0.33 +/- 0.19 to 0.17 +/- 0.18 mm); Ortho (0.24 +/- 0.15 to 0.16 +/- 0.15 mm)], indicating the need to understand how each metric is obtained and how to correctly interpret change in tumor size. CONCLUSIONS: In conclusion, micro-CT imaging provides a unique platform for in vivo longitudinal assessment of pulmonary lung cancer progression and potentially tracking of therapies at very high resolutions. The ability to evaluate the same subject over time provides for a sensitive assay that can be carried out on a smaller sample size. When integrated with image processing and analysis routines as detailed in this study, the data acquired from micro-CT imaging can now provide a very powerful assessment of pulmonary disease outcomes.

Assessment of transcriptomal analysis of Varicella-Zoster-virus gene expression in patients with and without post-herpetic neuralgia.

Varicella-Zoster virus (VZV) is a human herpes virus that reactivates from a latent state in human trigeminal and dorsal root ganglia to cause herpes zoster (shingles) which is a painful vesicular dermatomal skin eruption. The major complication of herpes zoster is post-herpetic neuralgia (PHN) which is a serious condition occurring especially in individuals over 50 years. PHN is extremely painful, may be permanent, and is frequently very refractory to all treatment. The ability to identify those patients with herpes zoster who are likely to develop PHN would be highly beneficial as it would allow pre-emptive anti-viral therapy. We have assessed the potential of using long oligonucleotide VZV microarrays to determine whether MeWo cells infected with VZV isolates obtained from 13 patients with zoster who had subsequently developed PHN showed significant transcriptomal differences from MeWo cells infected with viruses isolated from ten zoster patients who had not developed PHN. We found that viral gene expression from sample to sample within a group (PHN patients or non-PHN patients) varied as much, or more, than the viral gene expression between those groups. Quantitative real-time polymerase chain reaction studies carried out on 11 open reading frames on four representative viral infected MeWo cell lines (two from each group) confirmed the transcriptomal heterogeneity between the two groups. Growth curve analyses of ten representative infected cell lines (five from each group) showed that PHN and non-PHN-associated viruses replicated equally efficiently. Taken together, these findings suggest that viral microarray-based transcriptomal measurements are unlikely to prove of clinical utility in predicting the incidence of PHN.

Pulmonary hypertension in thoracic surgical patients.

PURPOSE OF REVIEW: Literature about thoracic surgery in patients with pulmonary hypertension is scarce. Perceived high risk has appropriately discouraged any unnecessary operation. However, the medical therapy for pulmonary hypertension has made great advances during the last decade. It is likely that future advances in survival and possibly the need for diagnostic procedures will increase the anesthesiologist's exposure to such patients. Understanding the unique physiology as well as new therapeutic agents will facilitate safe care for these challenging patients. RECENT FINDINGS: Since 1998, there have been three World Heath Organization symposiums on pulmonary hypertension. The most recent meeting in 2008 at Dana Point included revisions of the classification scheme and updates on new trials and therapies. New drugs have been utilized in cardiac, lung, or liver transplant operations to treat pulmonary hypertension. It is also recognized that one-lung ventilation presents unique problems for the patient with pulmonary hypertension. Inhalation use of the new pulmonary vasodilator drugs represents a new frontier for intraoperative pharmacology. SUMMARY: Here, the various types of pulmonary hypertension, physiologic changes, and new drug therapies are reviewed. Clinical experience with patients with pulmonary hypertension undergoing both nonthoracic and thoracic procedures is also reviewed. By identifying potential problem areas and application of new pharmacology, an approach to the patient with pulmonary hypertension is synthesized.

The Management of Diabetes in Everyday Life (MODEL) program: development of a tailored text message intervention to improve diabetes self-care activities among underserved African-American adults.

Tailoring health-related materials is an effective mechanism to encourage behavior change; however, little research has described processes and critical characteristics for effective tailoring in underserved populations. The purpose of this study is to describe a process using input from content experts and lay patient advisors to tailor text messages focused on improving self-care behaviors of African-American adults with diabetes and identify characteristics of messages perceived to be most effective. An initial library of tailorable messages was created using theory-based approaches, expert opinion, and publicly available materials. A study-specific advisory council representing the program's intended population provided sequential individual and focus group review of a sample of draft messages focused on medication use, healthy eating, and physical activity. Messages were reviewed for content, tone, and applicability to African-American adults with diabetes from underserved communities. Based on this feedback, messages were revised and a final library of tailorable messages was constructed for use in a text messaging intervention. The initial library had over 5,000 tailorable messages. Participants preferred messages that included: (1) encouraging statements without condescension; (2) short sentences in lay language; (3) specific, actionable instructions; and (4) content relatable to daily activities of living. When possible, messages with similar themes should be repeated over short periods of time to improve the odds of material being absorbed and action being taken. Input from patient participants and advisors is essential for designing deeply tailored messages that honor the preferences, values, and norms of the population under study and promote health behavior change. TRIAL REGISTRATION: NCT02957513.

Development and characterization of the novel human osteosarcoma cell line COS-33 with sustained activation of the mTOR pathway.

Outcomes have not improved for metastatic osteosarcoma for several decades. In part, this failure to develop better therapies stems from a lack of understanding of osteosarcoma biology, given the rarity of the disease and the high genetic heterogeneity at the time of diagnosis. We report here the successful establishment of a new human osteosarcoma cell line, COS-33, from a patient-derived xenograft and demonstrate retention of the biological features of the original tumor. We found high mTOR signaling activity in the cultured cells, which were sensitive to a small molecule inhibitor, rapamycin, a suppressor of the mTOR pathway. Suppressed mTOR signaling after treatment with rapamycin was confirmed by decreased phosphorylation of the S6 ribosomal protein. Increasing concentrations of rapamycin progressively inhibited cell proliferation in vitro. We observed significant inhibitory effects of the drug on cell migration, invasion, and colony formation in the cultured cells. Furthermore, we found that only a strong osteogenic inducer, bone morphogenetic protein-2, promoted the cells to differentiate into mature mineralizing osteoblasts, indicating that the COS-33 cell line may have impaired osteoblast differentiation. Grafted COS-33 cells exhibited features typical of osteosarcoma, such as production of osteoid and tumorigenicity in vivo. In addition, we revealed that the COS-33 cell line retained a complex karyotype, a homozygous deletion of the TP53 gene, and typical histological features from its original tumor. Our novel cellular model may provide a valuable platform for studying the etiology and molecular pathogenesis of osteosarcoma as well as for testing novel drugs for future genome-informed targeted therapy.

Genome-wide expression profiling of in vivo-derived bloodstream parasite stages and dynamic analysis of mRNA alterations during synchronous differentiation in Trypanosoma brucei.

BACKGROUND: Trypanosomes undergo extensive developmental changes during their complex life cycle. Crucial among these is the transition between slender and stumpy bloodstream forms and, thereafter, the differentiation from stumpy to tsetse-midgut procyclic forms. These developmental events are highly regulated, temporally reproducible and accompanied by expression changes mediated almost exclusively at the post-transcriptional level. RESULTS: In this study we have examined, by whole-genome microarray analysis, the mRNA abundance of genes in slender and stumpy forms of T.brucei AnTat1.1 cells, and also during their synchronous differentiation to procyclic forms. In total, five biological replicates representing the differentiation of matched parasite populations derived from five individual mouse infections were assayed, with RNAs being derived at key biological time points during the time course of their synchronous differentiation to procyclic forms. Importantly, the biological context of these mRNA profiles was established by assaying the coincident cellular events in each population (surface antigen exchange, morphological restructuring, cell cycle re-entry), thereby linking the observed gene expression changes to the well-established framework of trypanosome differentiation. CONCLUSION: Using stringent statistical analysis and validation of the derived profiles against experimentally-predicted gene expression and phenotypic changes, we have established the profile of regulated gene expression during these important life-cycle transitions. The highly synchronous nature of differentiation between stumpy and procyclic forms also means that these studies of mRNA profiles are directly relevant to the changes in mRNA abundance within individual cells during this well-characterised developmental transition.

Fluorescence lifetime imaging of quantum dot labeled DNA microarrays.

Quantum dot (QD) labeling combined with fluorescence lifetime imaging microscopy is proposed as a powerful transduction technique for the detection of DNA hybridization events. Fluorescence lifetime analysis of DNA microarray spots of hybridized QD labeled target indicated a characteristic lifetime value of 18.8 ns, compared to 13.3 ns obtained for spots of free QD solution, revealing that QD labels are sensitive to the spot microenvironment. Additionally, time gated detection was shown to improve the microarray image contrast ratio by 1.8, achieving femtomolar target sensitivity. Finally, lifetime multiplexing based on Qdot525 and Alexa430 was demonstrated using a single excitation-detection readout channel.

Advances in interventional pulmonology.

PURPOSE OF REVIEW: Interventional pulmonology is a rapidly expanding field offering less invasive therapeutic procedures for significant pulmonary problems. Many of the therapies may be new for the anesthesiologist. Although less invasive than surgery, some of these procedures will carry significant risks and complications. The team approach by anesthesiologist and pulmonologist is key to the success of these procedures. RECENT FINDINGS: Many modalities for central airway obstruction have emerged, including the expanding application of airway stenting procedures. Diagnostic bronchoscopy with ultrasound guidance promises great advances in lung cancer staging. New bronchoscopic treatments of asthma and emphysema are actively under investigation. Advances in anesthetic agents and techniques for interventional pulmonology procedures have also occurred. SUMMARY: This review is intended to familiarize the anesthesiologist with current and rising therapeutic modalities for pulmonary disease. Knowledge of interventional pulmonology facilitates planning and preparation for well tolerated and effective procedures.

A multiplexed protein microarray for the simultaneous serodiagnosis of human immunodeficiency virus/hepatitis C virus infection and typing of whole blood.

All donor blood samples must be tested pretransfusion to determine the donor blood type. Standard testing protocols require that assays be performed for important bloodborne pathogens such as hepatitis C, syphilis, hepatitis B, and human immunodeficiency virus. We have demonstrated proof of the concept that a protein microarray can type whole blood and detect antibody to significant pathogens simultaneously from the same donor blood sample. The data collected demonstrate the ability of the array to accurately type blood samples while also detecting the presence of antibodies against both human immunodeficiency virus and hepatitis C virus. In conclusion, we have successfully developed a platform capable of typing human whole blood samples, while at the same time testing for the presence of antibodies specific for human immunodeficiency virus/hepatitis C virus. The major benefits of this system are its amenability to expansion with additional assays, for example, rhesus typing and syphilis and/or hepatitis B virus detection, and also the adaptability of the assay to higher-throughput analysis, currently 16 individual samples per slide, but readily expandable to a 96-well format.

A menopause-specific quality of life questionnaire: development and psychometric properties.

OBJECTIVE: To develop a condition-specific quality of life questionnaire for the menopause with documented psychometric properties, based on women's experience. SUBJECTS: Women 2-7 years post-menopause with a uterus and not currently on hormone replacement therapy. Questionnaire development: A list of 106 menopause symptoms was reduced using the importance score method. Replies to the item-reduction questionnaire from 88 women resulted in a 30-item questionnaire with four domains, vasomotor, physical, psychosocial and sexual, and a global quality of life question. Psychometric properties: A separate sample of 20 women was used to determine face validity, and a panel of experts was used to confirm content validity. Reliability, responsiveness and construct validity were determined within the context of a randomized controlled trial. Construct validation involved comparison with the Neugarten and Kraines' Somatic, Psychosomatic and Psychologic subscales, the reported intensity of hot flushes, the General Well-Being Schedule, Channon and Ballinger's Vaginal Symptoms Score and Libido Index, and the Life Satisfaction Index. RESULTS: The face validity score was 4.7 out of a possible 5. Content validity was confirmed. Test-retest reliability measures, using intraclass correlation coefficients were 0.81, 0.79, 0.70 and 0.55 for the physical, psychosocial, sexual domains and the quality of life question. The intraclass correlation coefficient for the vasomotor domain was 0.37 but there is evidence of systematic change. Discriminative construct validity showed correlation coefficients of 0.69 for the physical domain, 0.66 and 0.40 for the vasomotor domain, 0.65 and -0.71 for the psychosocial domain, 0.48 and 0.38 for the sexual domain, and 0.57 for the quality of life question. Evaluative construct validity showed correlation coefficients of 0.60 for the physical domain, 0.28 for the vasomotor domain, 0.55 and - 0.54 for the psychosocial domain, 0.54 and 0.32 for the sexual domain, and 0.12 for the quality of life question. Responsiveness scores ranged from 0.78 to 1.34. CONCLUSIONS: The MENQOL (Menopause-Specific Quality of Life) questionnaire is a self-administered instrument which functions well in differentiating between women according to their quality of life and in measuring changes in their quality of life.

Evaluation of a protein microarray method for immuno-typing erythrocytes in whole blood.

All donor blood samples must be tested pre-transfusion to determine the blood type of donor erythrocytes, based on the ABO typing system. Current methods of testing are well characterised, but require a number of processing steps prior to analysis. In addition, standard testing protocols require additional assays such as hepatitis C and HIV testing be performed separately. We describe and evaluate a protein microarray platform for ABO blood typing that has the potential to be a simple reliable high throughput method, with the added capability for the integration of other important pre-transfusion tests. Sixty seven donor blood samples were incubated on microarrays printed with multiple spotted replicates of blood type antigen specific antibodies. We utilised a hold-out cross validation approach, combined with Receiver Operator Characteristic (ROC) curves to define thresholds within which a sample could be defined as being of a particular blood type. The threshold values from the ROC curve analysis demonstrated an excellent ability to accurately separate samples based on ABO blood type. The results obtained when the thresholds from the training sets were applied to test sets were also very encouraging, with misclassified samples being present in only 2 of the training sets and a mean classification error of 4.28%. When the mean thresholds were applied to the 67 donor samples, 95.5% were correctly blood typed (64 of 67 samples). We have demonstrated the ability of our protein microarray platform to successfully and accurately type human whole blood samples. We believe that this flexible platform provides a strong basis for an integrated approach for combined blood typing and pathogen testing in human whole blood.

Generation of a CLTA reporter human induced pluripotent stem cell line, CRMi001-A-1, using the CRISPR/Cas9 system to monitor endogenous clathrin trafficking.

The most highly studied endocytic pathway, clathrin-dependent endocytosis, mediates a wide range of fundamental processes including nutrient internalization, receptor recycling, and signal transduction. In order to model tissue specific and developmental aspects of this process, CRISPR/Cas9 genomic editing was utilized to fluorescently label the C-terminus of clathrin light chain A (CLTA) within the phenotypically normal, parental CRMi001-A human induced pluripotent stem cell line. Successfully edited cells were isolated by fluorescently activated cell sorting, remained karyotypically normal, and maintained their differentiation potential. This cell line facilitates imaging of endogenous clathrin trafficking within varied cell types.

Comparative performance of isometric and isotonic quadriceps strength testing in total knee arthroplasty.

BACKGROUND: Early quadriceps muscle strength assessment after a total knee arthroplasty (TKA) provides timely information on progress, but little is known about the pain profile and predictive validity associated with common clinical muscle strength tests. This study aimed to, in patients with a recent TKA, examine the associations of isometric and isotonic quadriceps strength with gait speed, accounting for knee pain experienced during testing. METHODS: A sample of 76 patients (mean age 68 years; 46 women) with a recent TKA (median, 1.5 months) participated. Quadriceps strength was measured on both limbs using a knee extension machine. Isotonic strength was assessed with a one-repetition maximum test. Isometric strength was measured at 40° and 70° of knee flexion using a custom-built load cell. To allow for valid comparisons between the tests, quadriceps strength symmetry ratios were calculated. Knee pain during testing was measured using an 11-point pain scale. Fast gait speed was measured using the 10-m walk test. RESULTS: Compared with isotonic test, quadriceps strength ratio was higher for the 40° flexion isometric test (P = 0.01), and this difference may be explained by the lower knee pain intensity elicited during the isometric tests (P's < 0.001). All strength measures were closely associated with fast gait speed after adjustment for knee pain and covariates (P's < 0.001). CONCLUSIONS: Early in the post-TKA period, isometric and isotonic strength tests may be used to assess quadriceps strength but these tests are not interchangeable. Isometric quadriceps testing may be preferable to isotonic testing as it was associated with lower knee pain intensity.

Technique, utility, and safety of awake tracheoplasty using combined laser and balloon dilation.

OBJECTIVES: Laryngotracheostenosis (LTS) is a condition in which the airway is narrowed between the vocal cords and the carina. We seek to examine whether flexible bronchoscopy with neodymium-doped yttrium aluminum garnet (Nd:YAG) laser incision and balloon dilation tracheoplasty is a practical choice in the management of patients with subglottic or tracheal stenosis. METHODS: A retrospective chart review was performed at a tertiary care hospital. All subjects with laryngotracheostenosis treated between January 1, 2000, and April 2005 who underwent endoscopic Nd:YAG laser incision and balloon dilation tracheoplasty performed using topical anesthesia and intravenous sedation were included. RESULTS: A total of 18 patients comprised the study and 36 procedures were performed without complication. Only one procedure was required by eight subjects, while five subjects required two procedures, three subjects had three procedures, one subject had four procedures, and one subject had five procedures until an adequate stable airway was obtained. The average follow-up was 22 months (range 3-55 months). The average body mass index (BMI) was 32.0 kg/m (range = 20.8-42.2 kg/m) and 11 of the 18 subjects (61.1%) were categorized as obese or morbidly obese by BMI criteria. CONCLUSION: Combined Nd:YAG laser incision and balloon dilation in an awake, spontaneously breathing patient is a safe and effective management tool in the treatment of laryngotracheostenosis. This technique may be particularly beneficial in patients who are at increased risk for general anesthesia such as those with morbid obesity or who have had a history of airway problems during anesthesia.

Management of obstructing pulmonary broncholithiasis with three-dimensional imaging and holmium laser lithotripsy.

Major airway obstruction due to broncholithiasis produces significant morbidity, and management is difficult. Many of the patients are elderly and are not good candidates for surgical removal. Bronchoscopic removal may be limited due to anatomic considerations, skill of the bronchoscopist, and exposure of the patient to additional procedural risks. Preprocedural planning with three-dimensional (3D) multidetector CT (MDCT) imaging enhances the bronchoscopist's knowledge of the relationships of the target lesions with critical structures, and improves the efficiency of the application of specific endobronchial therapies. Here we report our experience treating obstructing broncholithiasis in two patients utilizing pretreatment planning with 3D MDCT imaging, followed by bronchoscopically delivered holmium laser fragmentation of the stones.

Predictive performance of three multivariate difficult tracheal intubation models: a double-blind, case-controlled study.

We performed a case-controlled, double-blind study to examine the performance of three multivariate clinical models (Wilson, Arné, and Naguib models) in the prediction of unanticipated difficult intubation. The study group consisted of 97 patients in whom an unanticipated difficult intubation had occurred. For each difficult intubation patient, a matched control patient was selected in whom tracheal intubation had been easily accomplished. Postoperatively, a blinded investigator evaluated both patients. The clinical assessment included the patient's weight, height, age, Mallampati score, interincisor gap, thyromental distance, thyrosternal distance, neck circumference, Wilson risk sum score, history of previous difficult intubation, and diseases associated with difficult laryngoscopy or intubation. The Naguib model was significantly more sensitive (81.4%; P < 0.0001) than the Arné (54.6%) or Wilson (40.2%) models. Both the Naguib (76.8%) and Arné (74.7%) model classified more intubations correctly (P = 0.01) than the Wilson model (66.5%). The specificity of Arné, Wilson, and Naguib model was 94.9%, 92.8%, and 72.2%, respectively (P < 0.0001). The corresponding area under the receiver operating characteristic curve was 0.87, 0.79, and 0.82, respectively. Our new model for prediction of difficult intubation was developed using logistic regression and includes thyromental distance, Mallampati score, interincisor gap, and height. This model is 82.5% sensitive and 85.6% specific with an area under the receiver operating characteristic curve of 0.90.