Yet Another Doctor Blog On The Internet

Trial of pentoxifylline for diabetic impotence.


Chronic dosing with fluticasone propionate/salmeterol in a single device provides superior protection compared with an inhaled corticosteroid alone in protecting against exercise-induced asthma in children with persistent asthma.

Long-acting β2-agonist (LABA) monotherapy is contraindicated in asthma following reports of serious adverse events. Anonymised Scottish health data were used to determine the prevalence of LABA prescribing and LABA monotherapy (sustained and episodic) in asthma during 2006. Of 73 486 asthma patients identified, 5592 (7.6%; 95% CI 7.4% to 7.8%) were prescribed LABAs as a separate inhaler of which 991 patients had LABA monotherapy (17.7% (95% CI 16.7% to 18.7%) of patients at risk). Asthma reviews were associated with reductions in sustained (OR 0.44; 95% CI 0.32 to 0.61) but not episodic monotherapy (OR 1.16; 95% CI 0.85 to 1.57). These findings support recent changes in UK asthma guidelines recommending LABAs in fixed-dose combination inhalers.

The short term usage of budesonide decreases bronchial hyperresponsiveness, but nedocromil sodium and salmeterol in the given dises do not affect bronchial hyperresponsiveness.

To examine the systemic effects of single and chronic doses of salmeterol 100 microg.

To determine whether clinically relevant airspace concentrations of beta2-adrenergic agonists stimulated maximal alveolar fluid clearance rates and to determine whether beta2 agonist therapy decreased pulmonary edema in experimental acute lung injury.

Transmembrane domains (TMDs) I, II, and VII of the beta2-adrenergic receptor (beta2AR) were replaced, individually or in combination, with the corresponding regions of the beta1AR, and vice versa. The beta2-selective binding of salmeterol was not affected by the exchange of TMD I between the beta1- and beta2ARs. The affinity of salmeterol was slightly decreased (32-fold) by replacement of TMD II of the beta2AR with the homologous region of the beta1AR; the affinity was strongly decreased (1870-fold) for the beta2AR with TMD VII of the beta1AR. The affinity of salmeterol was partially restored by the introduction of TMD VII, but not TMD II, of the beta2AR into the beta1AR. By analyzing alanine-substituted mutants, we found that Tyr308 in TMD VII was mainly responsible for the high affinity binding of salmeterol. Two salmeterol derivatives with the ether oxygen at different positions in the side chain showed 33- and 64-fold decreased affinities for the wild-type beta2AR, and a derivative with no ether oxygen showed 147-fold decreased affinity for the wild-type beta2AR. These results indicate that Tyr308 in TMD VII is the major amino acid conferring the beta2-selective binding of salmeterol to the beta2AR and that the position of the ether oxygen in the side chain is also important for beta2-selective binding. A three-dimensional model of the salmeterol-beta2AR complex shows that the phenyl group of Tyr308 interacts with methylene groups near the protonated amine of salmeterol and the ether oxygen interacts with Tyr316.

The permeability of bovine pulmonary artery endothelial (CPAE) monolayers to Evans blue-labelled albumin (Evans blue-albumin) has been measured in vitro. Thrombin caused a concentration-dependent increase in Evans blue-albumin clearance across endothelial monolayers. Isoprenaline inhibited thrombin-induced Evans blue-albumin clearance in a concentration-dependent manner (EC50 21 nM). This effect was mimicked by the selective beta 2-adrenoceptor agonists salbutamol (EC50 64 nM) and salmeterol (EC50 2.7 nM), but not by the selective beta 1-adrenoceptor agonist, RO-363 ((1-[3',4'-dihydroxyphenoxy]-2-hydroxy-[3",4"- dimethoxyphenethylamino]-propane)oxalate), nor by the selective beta 3-adrenoceptor agonist, CL-316,243 (disodium (R,R)-5-[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]-amino]propyl]-1,3- benzodioxole-2,2-dicarboxylate). Isoprenaline, salbutamol and salmeterol, but not RO-363 or CL-316,243 produced small, but significant reductions in Evans blue-albumin clearance across unstimulated endothelial monolayers. Inhibition of the response to thrombin by isoprenaline was antagonised by the selective beta 2-adrenoceptor antagonist, ICI-118,551 ((erythro-DL-1(7-methylindan-4- yloxy)3-isopropylaminobutan-2-ol), pKB 8.4). Salmeterol also inhibited hydrogen peroxide-stimulated Evans blue-albumin clearance. Hence, the widely used beta 2-adrenoceptor agonists, salbutamol and salmeterol, are able to reduce endothelial permeability at nanomolar concentrations.

This retrospective, observational cohort study used health care claims data from January 2004 to June 2009 from a large administrative database for patients aged ≥40 years with COPD. Time-to-first COPD-related health care event beginning 30 days following therapy initiation with FSC (n = 16,684), ipratropium alone or in fixed dose combination with albuterol (n = 14,449), or tiotropium (n = 12,659) was estimated using Cox proportional hazard models that controlled for differences in patient demographic characteristics, health care utilization, and comorbidities at baseline. Mean adjusted costs and numbers of COPD-related health care encounters and prescription medication fills were compared among patients with 12 months of follow-up (FSC, n = 12,595; ipratropium, n = 10,617; tiotropium, n = 9126).