Structural properties of the HNF-1A transactivation domain.

Hepatocyte nuclear factor 1α (HNF-1A) is a transcription factor with important gene regulatory roles in pancreatic ß-cells. HNF1A gene variants are associated with a monogenic form of diabetes (HNF1A-MODY) or an increased risk for type 2 diabetes. While several pancreatic target genes of HNF-1A have been described, a lack of knowledge regarding the structure-function relationships in HNF-1A prohibits a detailed understanding of HNF-1A-mediated gene transcription, which is important for precision medicine and improved patient care. Therefore, we aimed to characterize the understudied transactivation domain (TAD) of HNF-1A in vitro. We present a bioinformatic approach to dissect the TAD sequence, analyzing protein structure, sequence composition, sequence conservation, and the existence of protein interaction motifs. Moreover, we developed the first protocol for the recombinant expression and purification of the HNF-1A TAD. Small-angle X-ray scattering and synchrotron radiation circular dichroism suggested a disordered conformation for the TAD. Furthermore, we present functional data on HNF-1A undergoing liquid-liquid phase separation, which is in line with in silico predictions and may be of biological relevance for gene transcriptional processes in pancreatic ß-cells.

Exploring Intra- and Inter-Regional Interactions in the IDP α-Synuclein Using smFRET and MD Simulations.

Theoretical concepts from polymer physics are often used to describe intrinsically disordered proteins (IDPs). However, amino acid interactions within and between regions of the protein can lead to deviations from typical polymer scaling behavior and even to short-lived secondary structures. To investigate the key interactions in the dynamic IDP α-synuclein (αS) at the amino acid level, we conducted single-molecule fluorescence resonance energy transfer (smFRET) experiments and coarse-grained molecular dynamics (CG-MD) simulations. We find excellent agreement between experiments and simulations. Our results show that a physiological salt solution is a good solvent for αS and that the protein is highly dynamic throughout its entire chain, with local intra- and inter-regional interactions leading to deviations from global scaling. Specifically, we observe expansion in the C-terminal region, compaction in the NAC region, and a slightly smaller distance between the C- and N-termini than expected. Our simulations indicate that the compaction in the NAC region results from hydrophobic aliphatic contacts, mostly between valine and alanine residues, and cation-π interactions between lysine and tyrosine. In addition, hydrogen bonds also seem to contribute to the compaction of the NAC region. The expansion of the C-terminal region is due to intraregional electrostatic repulsion and increased chain stiffness from several prolines. Overall, our study demonstrates the effectiveness of combining smFRET experiments with CG-MD simulations to investigate the key interactions in highly dynamic IDPs at the amino acid level.

SSIPTools: Software and Methodology for Surface Site Interaction Point (SSIP) Approach and Applications.

We present the SSIPTools suite of programs. SSIPTools is a collection of software modules enabling the use of the Surface Site Interaction Point (SSIP) molecular descriptors, used for the modeling of noncovalent interactions in neutral organic molecules. It contains an implementation of the workflow for the generation of the SSIP descriptors, as well as the Functional Group Interaction Profiles (FGIPs) and Solvent Similarity Indexes (SSIs) applications, based on the SSIMPLE (Surface Site Interaction model for the Properties of Liquids at Equilibria) approach.

Quality-of-life impact after in-office treatment of nasal valve obstruction with a radiofrequency device: 2-year results from a multicenter, prospective clinical trial.

BACKGROUND: Insufficiency of the nasal valve is increasingly being recognized as a cause of nasal airway obstruction. The condition is associated with many symptoms, including nasal congestion, sleep disturbance, snoring, and an overall decline in quality of life (QoL). An in-office, minimally invasive radiofrequency treatment of the nasal valve has been associated with improved symptoms of nasal obstruction and patients' QoL for a 6-month period in a noncontrolled, prospective, single-arm study. The purpose of this study was to determine whether the results achieved with radiofrequency treatment at 6 months would be sustained through 24 months. METHODS: Thirty-nine adult patients from an original cohort of 49 patients with severe to extreme Nasal Obstruction Symptom Evaluation (NOSE) Scale scores and dynamic or static internal nasal valve obstruction as the primary or significant contributor to obstruction were studied. Patients received intranasal bilateral radiofrequency treatment in a clinical study with a follow-up to 6 months, and were prospectively evaluated at 12, 18, and 24 months at 8 community-based otolaryngology practices. The patient-reported NOSE Scale score and 21 QoL questions were assessed. RESULTS: Clinically significant improvement from baseline in NOSE Scale score change demonstrated at 6 months (mean, 55.9; standard deviation [SD], 23.6; p < 0.0001) was maintained through 24 months (mean, 53.5; SD, 24.6; p < 0.0001). Responders (≥15-point improvement) consisted of 92.3% of participants at 6 months and 97.2% at 24 months. Responses to the QoL questions also showed improvement in patients' QoL. CONCLUSION: Treatment of the nasal valve with an in-office, transnasal temperature-controlled radiofrequency procedure was associated with stable and lasting improvement in symptoms of nasal obstruction and QoL through 24 months in this noncontrolled, single-arm study.

Solvent similarity index.

The Solvent Similarity Index (SSI) is a quantitative parameter we introduce for the comparison of the solvation properties of any solvent or solvent mixture. The Surface Site Interaction Model for Liquids at Equilibrium (SSIMPLE) was used to calculate the free energy of solvation of a single Surface Site Interaction Point (SSIP) on a solute. The SSIP representation of molecular surfaces was used to calculate the free energy of solvation for all possible solute polarities, generating a unique solvation profile for any solvent or solvent mixture. Quantitative comparison of the solvation profiles of two solvents was used as the basis for calculating the solvation similarity index. Values of SSI were calculated for all pairwise comparisons of 261 pure solvents at 298 K, and the results were used to classify solvents into groups according to their solvation properties. Applications to understanding the solvation properties of binary solvent mixtures and for identification of alternative solvents are illustrated.

Functional group interaction profiles: a general treatment of solvent effects on non-covalent interactions.

Solvation has profound effects on the behaviour of supramolecular systems, but the effects can be difficult to predict even at a qualitative level. Functional group interaction profiles (FGIPs) provide a simple visual method for understanding how solvent affects the free energy contribution due to a single point interaction, such as a hydrogen bond, between two solute functional groups. A generalised theoretical approach has been developed, which allows calculation of FGIPs for any solvent or solvent mixture, and FGIPs for 300 different solvents have been produced, providing a comprehensive description of solvent effects on non-covalent chemistry. The free energy calculations have been validated using experimental measurements of association constants for hydrogen bonded complexes in multiple solvent mixtures. The calculated FGIPs provide good descriptions of the solvation of polar solutes, solvophobic interactions between non-polar solutes in polar solvents like water, and preferential solvation in solvent mixtures. Applications are explored of the use of FGIPs in drug design, for optimising receptor-ligand interactions, and in enantioselective catalysis for solvent selection to optimise selectivity.

In-office treatment of nasal valve obstruction using a novel, bipolar radiofrequency device.

OBJECTIVES: To assess the safety and effectiveness of in-office bipolar radiofrequency treatment of nasal valve obstruction. STUDY DESIGN: Prospective, nonrandomized, multicenter case series. METHODS: Adult patients with a Nasal Obstruction Symptom Evaluation scale (NOSE) score ≥60 were selected. Patients were clinically diagnosed with dynamic or static internal nasal valve obstruction as primary or significant contributor to obstruction and were required to have a positive response to nasal mechanical dilators or lateralization maneuvers. Bilateral radio-frequency treatment was applied intranasally using a novel device, under local anesthesia in a single session. Safety and tolerance were assessed by event reporting, inspection, and Visual Analogue Scale (VAS) for pain. Efficacy was determined using the NOSE score and patient-reported satisfaction survey at 26 weeks. RESULTS: Fifty patients were treated. No device or procedure-related serious adverse events occurred. Soreness, edema, and crusting resolved by 1 month. The mean baseline NOSE score was 79.9 (SD 10.8, range 60-100), and all had severe or extreme obstruction. At 26 weeks, mean NOSE score was 69% lower at 24.7 (P < .0001) with 95% two-sided confidence intervals 48.5 to 61.1 for decrease. The decrease in NOSE score did not differ significantly between patients who did or did not have prior nasal surgery. Patient satisfaction mean by survey was 8.2 of 10. CONCLUSION: In office treatment of internal nasal valve obstruction using a bipolar radiofrequency device is safe and well-tolerated. Nasal obstruction, as assessed using the NOSE questionnaire at 26 weeks, was markedly improved with high patient satisfaction. LEVEL OF EVIDENCE: 2b, prospective cohort.

Understanding the Influence of Surface Solvation and Structure on Polymorph Stability: A Combined Mechanochemical and Theoretical Approach.

We explore the effect of solvent concentration on the thermodynamic stability of two polymorphs of a 1:1 cocrystal of theophylline and benzamide subjected to ball-mill liquid assisted grinding (LAG) and we investigate how this can be related to surface solvent solvation phenomena. In this system, most stable bulk polymorph form II converts to metastable bulk polymorph form I upon neat grinding (NG), while form I can fully or partially transform into form II under LAG conditions, depending on the amount of solvent used. Careful and strict experimental procedures were designed to achieve polymorph equilibrium under ball-mill LAG conditions for 16 different solvents. This allowed us to determine 16 equilibrium polymorph concentration curves as a function of solvent concentration. Ex-situ powder X-ray diffraction (PXRD) was used to monitor the polymorph concentration and crystallite size. The surface site interactions point (SSIP) description of noncovalent interactions was used in conjunction with the SSIMPLE method for calculating solvation energies to determine which functional groups are more or less exposed on the polymorph crystal surfaces. Our results demonstrate that (i) ball-mill LAG equilibrium curves can be successfully achieved experimentally for a cocrystal system; (ii) the equilibrium curves vary from solvent to solvent in onset values and slopes, thus confirming the generality of the interconversion phenomenon that we interpret here in terms of cooperativity; (iii) the concentration required for a switch in polymorphic outcome is dependent on the nature of the solvent; (iv) the SSIP results indicate that the theophylline π-system face is more exposed on the surface of form I while the theophylline N-methyl groups are more exposed in form II; and (v) for some solvents, form II has a significantly smaller crystal size at equilibrium than form I in the investigated solvent concentration range. Therefore, the free energy of the 1:1 cocrystal of theophylline and benzamide polymorphs studied here must be affected by surface solvation under ball-mill LAG conditions.

Oxidative purification of halogenated ferrocenes.

We report the large scale syntheses and 'oxidative purification' of fcI(2), fcBr(2) and FcBr (fc = ferrocene-1,1'-diyl, Fc = ferrocenyl). These valuable starting materials are typically laborious to separate via conventional techniques, but can be readily isolated by taking advantage of their increased E(1/2) relative to FcH/FcX contaminants. Our work extends this methodology towards a generic tool for the separation of redox active mixtures.

Laser-assisted low-dose retinoic acid in oral cancer chemoprevention.

OBJECTIVES: Systemic retinoic acid (RA) treatment for chemoprevention of squamous cell carcinoma of the head and neck (HNSCC) is limited by RA's toxic side effects at therapeutic doses. The pulsed-dye laser (PDL), through a mechanism of selective vascular targeting, may allow reduction of the RA dose to one that is better tolerated when these treatments are used in combination. This study tests our hypothesis that combination therapy of PDL irradiation and low-dose systemic RA is as effective as high-dose RA therapy alone in the chemoprevention of HNSCC. STUDY DESIGN: Randomized, prospective study in a hamster model. METHODS: Dysplastic lesions were induced in the cheek pouches of 48 hamsters by painting with topical 9,10-dimethl-1,2-benzanthrancene (DMBA). The hamsters were randomly divided into four treatment groups: 1) control (no treatment); 2) PDL irradiation only; 3) 5.0 mg RA (all-trans retinoid, 5.0 mg/kg per day, intraperitoneally [IP]); and (4) PDL + 0.5 mg RA (0.5 mg/kg per day, IP). The PDL irradiation was conducted at day 0 and 15, whereas the RA treatment was continued for 27 days. Tumor burden was measured over time. RESULTS: The lesions in all of three treatment groups grow more slowly than the untreated controls. The combination treatment of PDL and RA had the greatest inhibitory effect on tumors. CONCLUSION: This study suggests that combination treatment of PDL and low-dose RA is more effective than high-dose RA alone in the chemoprevention of HNSCC in a hamster cheek-pouch model, so that it should allow greatly improved tolerance of this regimen.

Hearing loss in Wegener's granulomatosis.

OBJECTIVE: To describe the frequency, type, and clinical course of hearing loss in Wegener's granulomatosis and assess hearing loss as an indicator of disease activity. STUDY DESIGN, SETTING, AND PATIENTS: Retrospective cohort review of all patients with Wegener's granulomatosis seen in 1 year at an academic medical center. MAIN OUTCOME MEASURES: Hearing loss documented by pure-tone audiogram. RESULTS: Thirty-six patients were included in the analysis: 20 men and 16 women, with a mean age of 55.5 years (range, 22-87 yr); 30 (83%) were antineutrophil cytoplasmic autoantibodies-positive, and the mean disease duration was 47 months (range, 2-196 mo). Twenty patients (56%) had documented hearing loss: there were 17 (47%) cases of sensorineural hearing loss and 12 (33%) cases of conductive hearing loss. Seven of 12 cases of conductive hearing loss improved with immunosuppressive treatment of Wegener's granulomatosis, 2 worsened, and 3 remained stable. Of 17 cases of sensorineural hearing loss, 3 improved, 4 worsened, and 10 remained stable. Seven patients had hearing loss requiring amplification. Five of 35 (14%) patients had established hearing loss months to years before diagnosis of Wegener's granulomatosis. Hearing loss occurred both on initial presentation and with disease relapse. The rates of conductive hearing loss (38%) and sensorineural hearing loss (31%) were also high in the subset of patients 65 years of age or younger and without history of noise exposure. CONCLUSIONS: Both sensorineural hearing loss and conductive hearing loss are common in Wegener's granulomatosis, may result in significant morbidity, and may precede the diagnosis of Wegener's granulomatosis by years. Both types of hearing loss in patients with Wegener's granulomatosis may be used as an indicator of disease. These data suggest that it may be appropriate to obtain screening audiograms in all patients with newly diagnosed or relapsing Wegener's granulomatosis.