Cross-α/ß polymorphism of PSMα3 fibrils.

The formation of ordered cross-ß amyloid protein aggregates is associated with a variety of human disorders. While conventional infrared methods serve as sensitive reporters of the presence of these amyloids, the recently discovered amyloid secondary structure of cross-α fibrils presents new questions and challenges. Herein, we report results using Fourier transform infrared spectroscopy and two-dimensional infrared spectroscopy to monitor the aggregation of one such cross-α-forming peptide, phenol soluble modulin alpha 3 (PSMα3). Phenol soluble modulins (PSMs) are involved in the formation and stabilization of Staphylococcus aureus biofilms, making sensitive methods of detecting and characterizing these fibrils a pressing need. Our experimental data coupled with spectroscopic simulations reveals the simultaneous presence of cross-α and cross-ß polymorphs within samples of PSMα3 fibrils. We also report a new spectroscopic feature indicative of cross-α fibrils.

Ames test study designs for nitrosamine mutagenicity testing: qualitative and quantitative analysis of key assay parameters.

The robust control of genotoxic N-nitrosamine (NA) impurities is an important safety consideration for the pharmaceutical industry, especially considering recent drug product withdrawals. NAs belong to the 'cohort of concern' list of genotoxic impurities (ICH M7) because of the mutagenic and carcinogenic potency of this chemical class. In addition, regulatory concerns exist regarding the capacity of the Ames test to predict the carcinogenic potential of NAs because of historically discordant results. The reasons postulated to explain these discordant data generally point to aspects of Ames test study design. These include vehicle solvent choice, liver S9 species, bacterial strain, compound concentration, and use of pre-incubation versus plate incorporation methods. Many of these concerns have their roots in historical data generated prior to the harmonization of Ames test guidelines. Therefore, we investigated various Ames test assay parameters and used qualitative analysis and quantitative benchmark dose modelling to identify which combinations provided the most sensitive conditions in terms of mutagenic potency. Two alkyl-nitrosamines, N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) were studied. NDMA and NDEA mutagenicity was readily detected in the Ames test and key assay parameters were identified that contributed to assay sensitivity rankings. The pre-incubation method (30-min incubation), appropriate vehicle (water or methanol), and hamster-induced liver S9, alongside Salmonella typhimurium strains TA100 and TA1535 and Escherichia coli strain WP2uvrA(pKM101) provide the most sensitive combination of assay parameters in terms of NDMA and NDEA mutagenic potency in the Ames test. Using these parameters and further quantitative benchmark dose modelling, we show that N-nitrosomethylethylamine (NMEA) is positive in Ames test and therefore should no longer be considered a historically discordant NA. The results presented herein define a sensitive Ames test design that can be deployed for the assessment of NAs to support robust impurity qualifications.

A theoretical analysis of coherent cross-peaks in polarization selective 2DIR for detection of cross-α fibrils.

The coupled amide-I vibrational modes in peptide systems such as fibrillar aggregates can often provide a wealth of structural information, although the associated spectra can be difficult to interpret. Using exciton scattering calculations, we characterized the polarization selective 2DIR peak patterns for cross-α peptide fibrils, a challenging system given the similarity between the monomeric and fibrillar structures, and interpret the results in light of recently collected 2D data on the cross-α peptide phenol soluble modulin α3. We find that stacking of α-helices into fibrils couples the bright modes across helical subunits, generating three new Bloch-like extended excitonic states that we designate A⊥, E∥, and E⊥. Coherent superpositions of these states in broadband 2DIR simulations lead to characteristic signals that are sensitive to fibril length and match the experimental 2DIR spectra.

The exploration of aza-quinolines as hematopoietic prostaglandin D synthase (H-PGDS) inhibitors with low brain exposure.

GlaxoSmithKline and Astex Pharmaceuticals recently disclosed the discovery of the potent H-PGDS inhibitor GSK2894631A 1a (IC50 = 9.9 nM) as part of a fragment-based drug discovery collaboration with Astex Pharmaceuticals. This molecule exhibited good murine pharmacokinetics, allowing it to be utilized to explore H-PGDS pharmacology in vivo. Yet, with prolonged dosing at higher concentrations, 1a induced CNS toxicity. Looking to attenuate brain penetration in this series, aza-quinolines, were prepared with the intent of increasing polar surface area. Nitrogen substitutions at the 6- and 8-positions of the quinoline were discovered to be tolerated by the enzyme. Subsequent structure activity studies in these aza-quinoline scaffolds led to the identification of 1,8-naphthyridine 1y (IC50 = 9.4 nM) as a potent peripherally restricted H-PGDS inhibitor. Compound 1y is efficacious in four in vivo inflammatory models and exhibits no CNS toxicity.

Resolution Enhancement in Wide-Field IR Imaging and Time-Domain Spectroscopy Using Dielectric Microspheres.

Wide-field imaging through dielectric microspheres has emerged in recent years as a simple and effective approach for generating super-resolution images at visible wavelengths. We present, to our knowledge, the first demonstration that dielectric microspheres can be used in a wide-field infrared (IR) microscope to enhance the far field resolution. We have observed a substantial improvement in resolution and magnification when images are collected through polystyrene microspheres. In addition, we demonstrate that spectroscopic imaging with a pulse-shaper based femtosecond mid-IR laser system is possible through the dielectric microspheres, which is a promising first step toward applying this technique to ultrafast IR imaging methods such as pump-probe and 2DIR microscopy.

The public health value of vaccines beyond efficacy: methods, measures and outcomes.

BACKGROUND: Assessments of vaccine efficacy and safety capture only the minimum information needed for regulatory approval, rather than the full public health value of vaccines. Vaccine efficacy provides a measure of proportionate disease reduction, is usually limited to etiologically confirmed disease, and focuses on the direct protection of the vaccinated individual. Herein, we propose a broader scope of methods, measures and outcomes to evaluate the effectiveness and public health impact to be considered for evidence-informed policymaking in both pre- and post-licensure stages. DISCUSSION: Pre-licensure: Regulatory concerns dictate an individually randomised clinical trial. However, some circumstances (such as the West African Ebola epidemic) may require novel designs that could be considered valid for licensure by regulatory agencies. In addition, protocol-defined analytic plans for these studies should include clinical as well as etiologically confirmed endpoints (e.g. all cause hospitalisations, pneumonias, acute gastroenteritis and others as appropriate to the vaccine target), and should include vaccine-preventable disease incidence and 'number needed to vaccinate' as outcomes. Post-licensure: There is a central role for phase IV cluster randomised clinical trials that allows for estimation of population-level vaccine impact, including indirect, total and overall effects. Dynamic models should be prioritised over static models as the constant force of infection assumed in static models will usually underestimate the effectiveness and cost-effectiveness of the immunisation programme by underestimating indirect effects. The economic impact of vaccinations should incorporate health and non-health benefits of vaccination in both the vaccinated and unvaccinated populations, thus allowing for estimation of the net social value of vaccination. CONCLUSIONS: The full benefits of vaccination reach beyond direct prevention of etiologically confirmed disease and often extend across the life course of a vaccinated person, prevent outcomes in the wider community, stabilise health systems, promote health equity, and benefit local and national economies. The degree to which vaccinations provide broad public health benefits is stronger than for other preventive and curative interventions.

Urinary incontinence persisting after childbirth: extent, delivery history, and effects in a 12-year longitudinal cohort study.

OBJECTIVE: To investigate the extent of persistent urinary incontinence (UI) 12 years after birth, and association with delivery-mode history and other factors. DESIGN: Twelve-year longitudinal cohort study. SETTING: Maternity units in Aberdeen, Birmingham, and Dunedin. POPULATION: Women who returned questionnaires 3 months and 12 years after index birth. METHODS: Data on all births over a period of 12 months were obtained from the units and then women were contacted by post. MAIN OUTCOME MEASURE: Persistent UI reported at 12 years, with one or more previous contact. RESULTS: Of 7879 women recruited at 3 months, 3763 (48%) responded at 12 years, with 2944 also having responded at 6 years; non-responders had similar obstetric characteristics. The prevalence of persistent UI was 37.9% (1429/3763). Among those who had reported UI at 3 months, 76.4% reported it at 12 years. Women with persistent UI had lower SF12 quality of life scores. Compared with having only spontaneous vaginal deliveries (SVDs), women who delivered exclusively by caesarean section were less likely to have persistent UI (odds ratio, OR 0.42, 95% CI 0.33-0.54). This was not the case in women who had a combination of caesarean section and SVD births (OR 1.01, 95% CI 0.78-1.30). Older age at first birth, greater parity, and overweight/obesity were associated with persistent UI. Of 54 index primiparae with UI before pregnancy, 46 (85.2%) had persistent UI. CONCLUSIONS: This study, demonstrating that UI persists to 12 years in about three-quarters of women, and that risk was only reduced with caesarean section if women had no other delivery mode, has practice implications. TWEETABLE ABSTRACT: A longitudinal study of 3763 women showed a prevalence of persistent UI 12 years after birth of 37.9%.

Genetic and Morphological Characterization of Freshwater Shrimps (Caridina africana Kingsley, 1882) Reveals the Presence of Alien Shrimps in the Cape Floristic Region, South Africa.

Morphological identification and molecular data (mtDNA COI) were used to resolve the taxonomic identity of a non-native freshwater shrimp in the Cape Floristic Region (CFR) of South Africa and to evaluate levels of genetic diversity and differentiation in the species' core natural distribution. The species was morphologically and genetically identified as Caridina africana Kingsley, 1882, whose main natural distribution is in the KwaZulu-Natal (KZN) Province, more than 1200 km from the point of new discovery. Subsequently, sequence data from natural populations occurring in seven rivers throughout KZN showed the presence of nuclear copies of the mtDNA COI gene (NUMTs) in 46 out of 140 individuals. Upon removal of sequences containing NUMTs, levels of genetic diversity were low in the alien population (possibly as a consequence of a bottleneck event), while varying levels of genetic diversity and differentiation were found in natural populations, indicating habitat heterogeneity, fragmentation and restricted gene flow between rivers. Following the present study, the alien shrimp has survived the Western Cape's winter and dispersed into a nearby tributary of the Eerste River System, hence posing an additional potential threat to endangered endemics. Understanding the biology of this alien species will aid detection and eradication procedures.

Optical excitation of Josephson plasma solitons in a cuprate superconductor.

Josephson plasma waves are linear electromagnetic modes that propagate along the planes of cuprate superconductors, sustained by interlayer tunnelling supercurrents. For strong electromagnetic fields, as the supercurrents approach the critical value, the electrodynamics become highly nonlinear. Josephson plasma solitons (JPSs) are breather excitations predicted in this regime, bound vortex-antivortex pairs that propagate coherently without dispersion. We experimentally demonstrate the excitation of a JPS in La1.84Sr0.16CuO4, using intense narrowband radiation from an infrared free-electron laser tuned to the 2-THz Josephson plasma resonance. The JPS becomes observable as it causes a transparency window in the opaque spectral region immediately below the plasma resonance. Optical control of magnetic-flux-carrying solitons may lead to new applications in terahertz-frequency plasmonics, in information storage and transport and in the manipulation of high-Tc superconductivity.

Management of chronic musculoskeletal pain.

Chronic musculoskeletal pain results from a complex interplay of mechanical, biochemical, psychological, and social factors. Effective management is markedly different from that of acute musculoskeletal pain. Understanding the physiology of pain transmission, modulation, and perception is crucial for effective management. Pharmacologic and nonpharmacologic therapies such as psychotherapy and biofeedback exercises can be used to manage chronic pain. Evidence-based treatment recommendations have been made for chronic pain conditions frequently encountered by orthopaedic surgeons, including low back, osteoarthritic, posttraumatic, and neuropathic pain. Extended-release tramadol; select tricyclic antidepressants, serotonin reuptake inhibitors, and anticonvulsants; and topical medications such as lidocaine, diclofenac, and capsaicin are among the most effective treatments. However, drug efficacy varies significantly by indication. Orthopaedic surgeons should be familiar with the widely available safe and effective nonnarcotic options for chronic musculoskeletal pain.

Faecal incontinence persisting after childbirth: a 12 year longitudinal study.

OBJECTIVES: To investigate persistent faecal incontinence (FI) 12 years after birth and association with delivery mode history and quality of life. DESIGN: Twelve-year longitudinal study. SETTING: Maternity units in Aberdeen, Birmingham and Dunedin. POPULATION: Women who returned questionnaires 3 months and 12 years after index birth. METHODS: Data on all births over 12 months were obtained from units and women were contacted 3 months, 6 years and 12 years post birth. MAIN OUTCOME MEASURE: Persistent FI, defined as reported at 12 years and one or more previous contacts. SF12 assessed quality of life. RESULTS: Of 7879 women recruited at 3 months, 3763 responded at 12 years, 2944 of whom also responded at 6 years: nonresponders were similar in obstetric factors. Prevalence of persistent FI was 6.0% (227/3763); 43% of 12-year responders who reported FI at 3 months also reported it at 12 years. Women with persistent FI had significantly lower SF12 scores. Compared with only spontaneous vaginal deliveries, women who had one or more forceps delivery were more likely to have persistent FI (odds ratio [OR] 2.08, 95% confidence interval [95% CI] 1.53-2.85) but it was no less likely with exclusively caesarean births (OR 0.93, 95% CI 0.54-1.58). More obese women than normal weight women reported persistent FI (OR 1.52, 95% CI 1.06-2.17). CONCLUSIONS: This longitudinal study has demonstrated persistence of FI many years after birth and shown that one forceps birth increased the likelihood, whereas exclusive caesarean birth showed no association. Obesity, which increased symptom likelihood, is a modifiable risk factor.

Childbirth and prolapse: long-term associations with the symptoms and objective measurement of pelvic organ prolapse.

OBJECTIVES: To investigate prolapse symptoms and objectively measured pelvic organ prolapse, 12 years after childbirth, and association with delivery mode history. DESIGN: Twelve-year longitudinal study. SETTING: Maternity units in Aberdeen, Birmingham and Dunedin. POPULATION: Women dwelling in the community. METHODS: Data from women were collected 12 years after an index birth and women were invited for examination. Logistic regression investigated associations between risk factors and prolapse symptoms and signs. MAIN OUTCOME MEASURES: Prolapse symptom score (POP-SS); objectively measured prolapse (POP-Q). RESULTS: Of 7725 continuing women, 3763 (49%) returned questionnaires at 12 years. The median POP-SS score was 2 (IQR 0-4). One or more forceps deliveries (OR 1.20, 95% CI 1.04-1.38) and a body mass index (BMI) over 25 were associated with higher (worse) POP-SS scores, but age over 25 years at first delivery was associated with lower (better) scores. There was no protective effect if all deliveries were by caesarean section (OR 0.84, 95% CI 0.69-1.02). Objective prolapse was found in 182/762 (24%) women. Women aged over 30 years when having their first baby and parity were significantly associated with prolapse. Compared with women whose births were all spontaneous vaginal deliveries, women who had all births by caesarean section were the least likely to have prolapse (OR 0.11, 95% CI 0.03-0.38), and there was a reduced risk after forceps or a mixture of spontaneous vaginal delivery and caesarean section. CONCLUSIONS: These findings are at odds with each other, suggesting that prolapse symptoms and objective prolapse may not be in concordance, or are associated with different antecedent factors. Further follow-up is planned.

Hypertrophy of the sublime tubercle in elbow ulnar collateral ligament injuries: a case series of baseball pitchers undergoing ulnar collateral ligament reconstruction with short-term follow-up.

Background: The ulnar collateral ligament (UCL) of the elbow is subject to repetitive stress in overhead throwing athletes. This can lead to morphologic changes at the bony attachments of the UCL and hypertrophy of the sublime tubercle. The purpose of this case series is to describe the surgical details and clinical outcomes of a series of competitive baseball pitchers with hypertrophic sublime tubercles who underwent UCL reconstruction (UCLR). Methods: All baseball pitchers who were treated for UCL injuries with significant hypertrophy of the sublime tubercle on preoperative imaging were included in the series. Clinical history, preoperative imaging, intraoperative findings during UCLR, and postoperative outcomes measured with the Conway scale were described. Results: Ten players (average age of 22.9 years [range 13-39]) were included (average follow-up 20.4 months [range 3-38 months]). Five patients also had symptoms of ulnar nerve compression, with 4 requiring transposition at the time of ULCR and 1 at 3 months postoperatively. Bony hypertrophy of the sublime tubercle was confirmed intraoperatively in all cases and excised before UCLR with the docking technique. Of the 7 patients with at least 12-month follow-up postoperatively, 6 had excellent outcomes, and 1 had a fair outcome. Conclusion: Although UCLR in the setting of hypertrophic sublime tubercle can be more complex than typical UCLR, excellent outcomes are achievable with preoperative recognition and surgical planning.

Polaronic conductivity in the photoinduced phase of 1T-TaS2.

The transient optical conductivity of photoexcited 1T-TaS2 is determined over a three-order-of-magnitude frequency range. Prompt collapse and recovery of the Mott gap is observed. However, we find important differences between this transient metallic state and that seen across the thermally driven insulator-metal transition. Suppressed low-frequency conductivity, Fano phonon line shapes, and a midinfrared absorption band point to polaronic transport. This is explained by noting that the photoinduced metallic state of 1T-TaS2 is one in which the Mott gap is melted but the lattice retains its low-temperature symmetry, a regime only accessible by photodoping.

Clocking the melting transition of charge and lattice order in 1T-TaS2 with ultrafast extreme-ultraviolet angle-resolved photoemission spectroscopy.

We use time- and angle-resolved photoemission spectroscopy with sub-30-fs extreme-ultraviolet pulses to map the time- and momentum-dependent electronic structure of photoexcited 1T-TaS(2). This compound is a two-dimensional Mott insulator with charge-density wave ordering. Charge order, evidenced by splitting between occupied subbands at the Brillouin zone boundary, melts well before the lattice responds. This challenges the view of a charge-density wave caused by electron-phonon coupling and Fermi-surface nesting alone, and suggests that electronic correlations play a key role in driving charge order.

Wound healing following combined radiation and cetuximab therapy in head and neck cancer patients.

OBJECTIVE: This study set out to determine if cetuximab treatment increases the risk of wound healing complications when combined with radiation therapy. METHOD: We performed a retrospective chart review of head and neck cancer patients who received salvage neck dissections between 1999 and 2007, at two academic tertiary care centres. Complications from wound healing were compared between radiation and combined therapy groups. RESULTS: A total of 35 patients received radiation (n=20) or combined radiation and cetuximab therapy (n=15) prior to neck dissection. The treatment groups were similar in regard to demographic and primary tumour-related characteristics. The time between treatment and salvage neck dissection did not differ between the radiation (3.9 months) and combination treatment (3.0 months) groups (p=0.15). Wound healing complications occurred in 13% (2/15) of the patients treated with radiation and cetuximab and there were no complications in patients who received radiation alone (p=0.20). CONCLUSION: Cetuximab did not significantly increase the risk of post-surgical wound complications, although a higher absolute number of wound complications was observed in the group treated with cetuximab and radiation therapy, compared with the group treated with radiation alone. CONFLICT OF INTEREST: This work was supported by a grant from the National Institute of Health (2T32 CA091078-06). One of the authors, JAB, is an occasional consultant and honoraria for ImClone and Bristol-Meyers Squibb.

Acute Herpes Simplex Esophagitis in an Immunocompetent Adult with Eosinophilic Esophagitis.

Herpes simplex esophagitis (HSE) represents a rare entity in immunocompetent patients and has infrequently been described in association with eosinophilic esophagitis (EoE). Causality in this rare association remains a debated topic. We present a case of HSE occurring in an immunocompetent adult with EoE and review the literature in support of EoE induced mucosal disruption predisposing to increased risk of HSE.

Fluoroquinolones in the management of community-acquired pneumonia.

AIMS: Review of the current guidelines for the use of respiratory fluoroquinolones in the management of community-acquired pneumonia (CAP). METHODS: Data were collected from recent clinical trials on fluoroquinolone therapy in patients with CAP and from updated recommendations of antimicrobial therapy in managing CAP, with a focus on current North American guidelines. RESULTS: Randomised clinical trials of respiratory fluoroquinolones (moxifloxacin, levofloxacin and gemifloxacin) in the treatment of CAP were identified and analysed. The bacteriology of CAP, and susceptibility rates, resistance rates and pharmacokinetic and pharmacodynamic properties of fluoroquinolones against causative pathogens in CAP, and adverse event profiles of these agents were described. Respiratory fluoroquinolones have broad-spectrum antibacterial activities against common causative pathogens in CAP and provide an important treatment option as monotherapy for outpatients with comorbidities and inpatients who are not admitted to the intensive care unit (ICU), including those with risk factors of drug-resistant Streptococcus pneumoniae. For treatment of ICU patients with severe CAP, it is recommended that fluoroquinolones be used in combination with a beta-lactam. Recent studies also demonstrated a more rapid resolution of clinical symptoms with the use of highly potent respiratory fluoroquinolones. DISCUSSION: Appropriate use of fluoroquinolone agents may shorten the duration of antimicrobial therapy and the length of hospital stay and contribute to the decreased development of resistance in patients with CAP. Adverse event profiles of these agents should be considered to facilitate the selection of an appropriate fluoroquinolone for appropriate CAP patients. CONCLUSION: The fluoroquinolone class, specifically those with adequate activity against respiratory pathogens, represents an important and convenient treatment option for patients with CAP.

Effects of including raw or extruded field peas (Pisum sativum L.) in diets fed to weanling pigs.

BACKGROUND: There is limited information about the response to field peas fed to weanling pigs. Two experiments were therefore conducted to investigate effects of including increasing levels of field peas in weanling pig diets. RESULTS: In Experiment 1, a reduction (linear, P < 0.05) in average daily gain (551, 574, 541, 548, 512 and 533 g d(-1)) was observed in response to increasing levels of raw field peas (0, 120, 240, 360, 480 and 600 g kg(-1)) in diets fed from day 14 to 42 post weaning. In Experiment 2, the inclusion of raw field peas (0, 245 or 490 g kg(-1)) in the diets reduced (linear, P < 0.05) feed intake from day 14 to 39 post weaning, but average daily gain and gain:feed were unaffected by the use of raw field peas. The response to extruded field peas was not different from that to raw field peas. CONCLUSION: Up to 360 g kg(-1) raw field peas may be included in nursery diets without negatively influencing pig growth performance provided that diets are balanced for indispensable amino acids. Results from this work do not support any advantage of extruding the field peas.

Does liquid-liquid phase separation drive peptide folding?

Proline-arginine (PR) dipeptide repeats have been shown to undergo liquid-liquid phase separation and are an example of a growing number of intrinsically disordered proteins that can assemble into membraneless organelles. These structures have been posited as nucleation sites for pathogenic protein aggregation. As such, a better understanding of the effects that the increased local concentration and volumetric crowding within droplets have on peptide secondary structure is necessary. Herein we use Fourier transform infrared (FTIR) and two-dimensional infrared (2DIR) spectroscopy to show that formation of droplets by PR20 accompanies changes in the amide-I spectra consistent with folding into poly-proline helical structures.