Theory of chain walking catalysis: From disordered dendrimers to dendritic bottle-brushes.

The chain walking (CW) polymerization technique has the unique property of a movable catalyst synthesizing its own path by creating branch-on-branch structures. By successive attachment of monomers, the resulting architecture ranges from dendritic to linear growth depending on the walking rate, which is defined by the ratio of walking steps and reaction events of the catalyst. The transition regime is characterized by local dendritic sub-structures (dendritic blobs) and a global linear chain feature forming a dendritic bottle-brush.

Temperature-Induced Mechanomodulation of Interpenetrating Networks of Star Poly(ethylene glycol)-Heparin and Poly(-isopropylacrylamide).

Thermoresponsive interpenetrating networks (IPNs) were prepared by sequential synthesis of a biohybrid network of star-shaped poly(ethylene glycol) [starPEG] and heparin and a poly(-isopropylacrylamide)-polymer network. Amide bond formation was used for cross-linking of the starPEG-heparin network and photo-cross-linking with ,'-methylenebis(acrylamide) was applied for the formation of the second polymer network. Both networks were linked by chain entanglements and hydrogen bonds only.

Polyolefins Formed by Chain Walking Catalysis-A Matter of Branching Density Only?

Recently developed chain walking (CW) catalysis is an elegant approach to produce materials with controllable structure and properties. However, there is still a lack in understanding of how the reaction mechanism influences the macromolecular structures. In this study, a series of dendritic polyethylenes (PE) synthesized by Pd-α-diimine-complex through CW catalysis (CWPE) is investigated by means of theory and experiment.

[The first biologic for rheumatoid arthritis: factors influencing the therapeutic decision].

Background And Aims: Biologics (disease modifying antirheumatic drugs, bDMARD) have been in use in Germany for the treatment of rheumatoid arthritis (RA) since 2001, usually after failure of at least one conventional synthetic (cs)DMARD. We analyzed temporal changes in factors that influence the decision for either a first bDMARD or a further csDMARD.

Material And Methods: We analyzed data from 9513 bDMARD-naive RA patients in the German biologics register RABBIT who switched to a new therapy.

Biohybrid networks of selectively desulfated glycosaminoglycans for tunable growth factor delivery.

Sulfation patterns of glycosaminoglycans (GAG) govern the electrostatic complexation of biomolecules and thus allow for modulating the release profiles of growth factors from GAG-based hydrogels. To explore options related to this, selectively desulfated heparin derivatives were prepared, thoroughly characterized, and covalently converted with star-shaped poly(ethylene glycol) into binary polymer networks. The impact of the GAG sulfation pattern on the network characteristics of the obtained hydrogels was theoretically evaluated by mean field methods and experimentally analyzed by rheometry and swelling measurements.

Two universality classes for random hyperbranched polymers.

We grow AB2 random hyperbranched polymer structures in different ways and using different simulation methods. In particular we use a method of ad hoc construction of the connectivity matrix and the bond fluctuation model on a 3D lattice. We show that hyperbranched polymers split into two universality classes depending on the growth process.

Fluctuation driven height reduction of crosslinked polymer brushes: a Monte Carlo study.

We study the changes in the conformations of brushes upon the addition of crosslinks between the chains using the bond fluctuation model. The Flory-Rehner model applied to uniaxially swollen networks predicts a collapse for large degrees of crosslinking q proportional to q(-1∕3) in disagreement with our simulation data. We show that the height reduction of the brushes is driven by monomer fluctuations in a direction perpendicular to the grafting plane and not due to network elasticity.

Impact of modified-release prednisone on functional ability in patients with rheumatoid arthritis.

This observational study assessed functional ability in patients treated with modified-release prednisone under conditions of normal clinical practice. Patients treated with modified-release prednisone were observed over 9 months. The primary outcome measure was the change from baseline total score using the Questionnaire on Activity Status (QAS); total QAS score ranges from 0 (severely impaired) to 100 (completely unimpaired).

A model for segregation of chromatin after replication: segregation of identical flexible chains in solution.

We study the segregation of two long chains from parallel but randomly twisted start conformations under good solvent conditions using Monte Carlo simulations to mimic chromatin segregation after replication in eukaryotic cells in the end of prophase. To measure the segregation process, we consider the center-of-mass separation between the two chains and the average square distance between the monomers which were connected before segregation starts. We argue that segregation is dominated by free diffusion of the chains, assuming that untwisting can be achieved by Rouse-like fluctuations on the length scale of a twisted loop.

Immunotherapy throughout the decades: from Noon to now.

Objective: To review major milestones in the development of subcutaneous allergen immunotherapy in 20-year segments.

Data Sources: Review of the literature available in textbooks and journals.

Study Selection: Articles and books addressing major achievements in the development of subcutaneous allergy immunotherapy were selected for inclusion in this review.

Comparative effectiveness of tumour necrosis factor alpha inhibitors in combination with either methotrexate or leflunomide.

Objective: The objective of this study was to compare the effectiveness of a combination of tumour necrosis factor alpha (TNFalpha) inhibitors with either methotrexate or leflunomide in the treatment of patients with rheumatoid arthritis in a real-world setting.

Methods: Data from 1769 outpatients enrolled in the German biologics register RABBIT who were treated with one of the TNFalpha inhibitors adalimumab, etanercept, or infliximab in combination with either methotrexate (n = 1375) or leflunomide (n = 394) were included in the analysis. Clinical status including disease activity as well as treatment data were documented by the treating rheumatologist at baseline and at 3, 6, 12, 18, 24, 30 and 36 months of follow-up.

A new solution-based intranasal triamcinolone acetonide formulation in patients with perennial allergic rhinitis: how does the pharmacokinetic/pharmacodynamic profile for cortisol suppression compare with an aqueous suspension-based formulation?

The present study was undertaken to describe the pharmacokinetics of a new solution-based intranasal triamcinolone acetonideformulation (Tri-Nasal) in patients with perennial allergic rhinitis and to use a pharmacokinetic/pharmacodynamic (PK/PD) simulation approach to compare the potential effects on plasma cortisol with that of an aqueous suspension-based nasal triamcinolone acetonide formulation (Nasacort AQ). Data from an open-label, randomized, three-way crossover study in patients with perennial allergic rhinitis receiving three doses (100, 200, and 400 microg) of a nasal solution-based triamcinolone acetonide formulation (Tri-Nasal) over 7 days were used to describe the pharmacokinetics of this formulation. Available literature data for a suspension-based aqueous triamcinolone acetonide formulation (Nasacort AQ) were used to describe its pharmacokinetic profile after similar single doses of 110, 220, and 440 microg.

Comparison of the effects of intravenous and oral montelukast on airway function: a double blind, placebo controlled, three period, crossover study in asthmatic patients.

Background: Montelukast, a leukotriene receptor antagonist, improves parameters of asthma control including forced expiratory volume in one second (FEV(1)) when given orally to patients aged six years or older. This study was undertaken to compare the effect on FEV(1) of intravenous and oral montelukast and placebo during the 24 hour period following administration.

Methods: Fifty one asthmatic patients (FEV(1) 40-80% predicted and > or =15% improvement after inhaled beta agonist) were enrolled in a double blind, single dose, three period, crossover study to receive intravenous montelukast (7 mg), oral montelukast (10 mg), or placebo in a randomised fashion.

Correlation of cat-hair (Fel d1) prick skin test to airway response using a live-cat-room challenge model.

The purpose of this study was to document the relationship between prick skin test, airway, and common allergy symptom responses to natural cat exposure. Twenty-nine volunteers with a history of cat-hair allergy and asthma were recruited. Subjects had spirometry and prick skin test with Fel d1 on Visit 1.

Proventil HFA prevents exercise-induced bronchoconstriction in children.

Short-acting inhaled beta2-agonists used just prior to exercise are an effective method for preventing exercise-induced bronchoconstriction (EIB) in children. This was a randomized, single-blind, placebo-controlled, four-period crossover study that compared the effectiveness of albuterol formulated in hydrofluoroalkane-134a (HFA) to albuterol formulated in chlorofluorocarbons (CFCs) and to placebo in protecting asthmatic children age 6-11 from EIB. Patients self-administered either HFA albuterol, two different CFC albuterol products, or placebo 30 min prior to exercise challenge.

Dose-proportional pharmacokinetics of budesonide inhaled via Turbuhaler.

Aims: The present pharmacokinetic study was undertaken to determine the dose proportionality of three different doses of budesonide-400 microg, 800 microg or 1600 microg administered twice daily by a dry-powder inhaler (Turbuhaler ) in adult patients with mild asthma.

Methods: A total of 38 patients received budesonide by inhalation, 13 received 400 microg twice daily, 12 received 800 microg twice daily and 13 received 1600 microg twice daily. Mean FEV1 at inclusion was 3.

Therapeutic equivalence of Spiros dry powder inhaler and Ventolin metered dose inhaler. A bioassay using methacholine.

Because chlorofluorocarbons (CFCs) contribute to depletion of stratospheric ozone, CFC-containing metered-dose inhalers (MDIs) such as Ventolin and Proventil are being phased out of production. In terms of delivery of albuterol to the lungs, we compared an alternative delivery system, the Spiros dry-powder inhaler (DPI), with Ventolin, using a methacholine challenge-based clinical bioassay. Twenty-four adults and adolescents with asthma completed this double-blind, four-period crossover study.

A dose-ranging study of mometasone furoate aqueous nasal spray in children with seasonal allergic rhinitis.

Background: The efficacy and safety of mometasone furoate aqueous nasal spray (MFNS; Nasonex) 200 microg once daily for the treatment and prophylaxis of seasonal allergic rhinitis (SAR) and treatment of perennial rhinitis have been demonstrated in adults. However, the dose response of MFNS in pediatric patients has not yet been characterized.

Objective: This study was conducted to determine the dose-response relationship of 3 different doses of MFNS in a pediatric population.

Adrenal effects and pharmacokinetics of CFC-free beclomethasone dipropionate: a 14-day dose-response study.

Since equivalent efficacy is achieved with lower doses of the reformulated beclomethasone dipropionate in the chlorofluorocarbon (CFC)-free propellant HFA-134a (HFA) than with the original CFC-beclomethasone dipropionate formulation, it is possible the HFA-beclomethasone dipropionate may have less safety concerns than the CFC formulation. Despite its chronic use, the steady-state pharmacokinetics of beclomethasone dipropionate has never been studied before. This double-blind study examined adrenal effects and pharmacokinetics after 14 days of dosing with HFA-beclomethasone dipropionate.

Ipratropium bromide nasal spray 0.03% and beclomethasone nasal spray alone and in combination for the treatment of rhinorrhea in perennial rhinitis.

Background: Perennial rhinitis is a common condition that affects up to 10% to 20% of the population. Multiple agents are frequently administered since no single agent provides complete relief. Studies assessing the benefit/risk of combined therapy are important especially for newly approved agents such as ipratropium bromide nasal spray 0.

Tri-Nasal triamcinolone acetonide nasal spray 200 and 400 micrograms qd versus placebo and Nasacort triamcinolone acetonide nasal aerosol 440 micrograms qd in patients suffering from seasonal allergic rhinitis during the grass season.

Tri-Nasal Nasal Spray is an investigational solution of triamcinolone acetonide (TAA) currently being evaluated as a treatment for allergic rhinitis. The safety and efficacy of 200 and 400 micrograms once daily doses of Tri-Nasal Nasal Spray, an active control (440 micrograms once daily of Nasacort Nasal aerosol), and Tri-Nasal Nasal Spray placebo were compared over a 2-week treatment period in a double-blind (the Nasacort treatment was not blinded), parallel design trial. A total of 377 adult patients in 13 centers were enrolled during the grass pollen season.

Montelukast once daily inhibits exercise-induced bronchoconstriction in 6- to 14-year-old children with asthma.

Objective: To determine whether montelukast, a leukotriene receptor antagonist, attenuates exercise-induced bronchoconstriction (EIB) in 6- to 14-year-old children with asthma.

Study Design: Double-blind, multicenter, 2-period crossover study. Children (n = 27) with forced expiratory volume in 1 second (FEV1) > or =70% of the predicted value and a fall in FEV1 > or =20% after exercise on 2 occasions.

Effect of fluticasone propionate aqueous nasal spray versus oral prednisone on the hypothalamic-pituitary-adrenal axis.

Background: Fluticasone propionate is a glucocorticoid with negligible oral bioavailability and very low intranasal bioavailability that is used as an intranasal spray for the treatment of rhinitis.

Objective: The purpose of this study was to evaluate the hypothalamic-pituitary-adrenal (HPA)axis effects of fluticasone propionate aqueous nasal spray (FP ANS) compared with oral prednisone and placebo by using a 6-hour cosyntropin infusion test.

Methods: In a 4-week, randomized, double-blind, double-dummy, placebo-controlled parallel-group study, 105 adult patients with allergic rhinitis were randomly assigned to receive FP ANS 200 microg once daily, FP ANS 400 microg twice daily, oral prednisone 7.

Montelukast, a leukotriene-receptor antagonist, for the treatment of mild asthma and exercise-induced bronchoconstriction.

Background: Patients with mild asthma frequently have only exercise-induced bronchoconstriction, a symptom of inadequate control of asthma. We evaluated the ability of montelukast, a leukotriene-receptor antagonist, to protect such patients against exercise-induced bronchoconstriction.

Methods: We randomly assigned 110 patients (age, 15 to 45 years) with mild asthma and a decrease in the forced expiratory volume in one second (FEV1) of at least 20 percent after exercise on two occasions during a placebo run-in period to receive 10 mg of montelukast (54 patients) or placebo (56 patients) once daily at bedtime for 12 weeks in a double-blind study.