Can a newβ 2-agonist reduce the mortality of asthma?

Tulobuterol is a syntheticβ-adrenergic agonist which, when administered orally, is a potent, long-acting bronchodilator. The safety and efficacy of 2 mg tulobuterol tablets taken twice daily was compared to that of 4 mg salbutamol tablets taken three times daily for a period of 12 weeks in outpatients with stable chronic asthma in a randomized, double-blind, multi-center study conducted in Australia. Strict entry criteria were employed; only those patients whose baseline FEV₁ value was between 40–70% of the predicted normal value and increased at leást 20% after two inhalations of a metered dose (250μg per dose) of terbutaline aerosol at a screening visit were included. Treatment with active study drug was preceded by a 2 week single-blind, placebo lead-in period. The onset and duration of the bronchodilating effect was studied on the first day of the placebo lead-in period and on the first and last days of the 12 week parallel design treatment period. Of 140 patients enrolled, 73 had tulobuterol and 67 had salbutamol. Of these, 61 tulobuterol and 59 salbutamol treated patients could be evaluated for efficacy. Of the 140 patients, 129 completed the study. All patients were issued a mini peak flow meter and diary cards to record daily PEFRs and symptoms of airways obstruction throughout the study. The demographics of the patients in both treatment groups were similar in all modalities: they were comparable in age, duration of asthma, mean FEV₁ (expressed as percent of predicted normal), and reversibility (as demonstrated by an increase in FEV₁ after administration of aβ ₂-agonist aerosol). Tulobuterol appeared to have a longer duration of action than salbutamol and was more effective as a bronchodilator when compared using simple spirometry measurements. The tulobuterol treated group showed an improvement in predosing FEV₁ at each visit throughout the duration of the study. This appeared to be paralleled by patients’ subjective experience of fewer nocturnal symptoms (diary cards). Adverse events were comparable in both groups—35.6% (26 of 73) in the tulobuterol group and 44.8% (30 of 67) in the salbutamol group. Tremor was the predominant side effect reported—33% of tulobuterol and 40% of salbutamol patients. This was mostly reported as mild to moderate in severity. Only 4 tulobuterol and 3 salbutamol patients rated tremor as severe; 3 tulobuterol and 2 salbutamol patients were prematurely withdrawn from the study on account of side effects. Tulobuterol in tablet form is a new, safe, effective bronchodilator for the treatment of asthma. The twice-daily dosing regime can be expected to improve patient compliance and avert the problems associated with poor aerosol administration techniques. The results in this study suggest that tulobuterol will occupy a special place in the treatment of noctural asthma. It would appear a reasonable proposition that tulobuterol will help to control symptoms better, and thus lessen morbidity, with the eventual result, hopefully, of a reduction in mortality.     

β-Agonistic properties of tulobuterol,a newβ-sympathicomimetic Drug,and its effects on pulmonaryβ-adrenoceptor characteristics

Radioligand binding studies have been developed to determine pharmacologic receptor characteristics in vitro. With this assay, not only the number and dissociation constant (K _d ) can be studied, but also the interaction of agonists with the receptor. We used this method to study a newβ ₂-sympathicomimetic drug, tulobuterol (1-(0-chlorophenyl)-2-butylaminoethanol hydrochloride). Two sets of experiments were performed. One set of experiments investigated the effects of tulobuterol and terbutaline in chronic administration, while the second set compared theβ-adrenoceptor-stimulating properties of tulobuterol with terbutaline and salbutamol. The effects of 10 days’ administration of tulobuterol and terbutaline onβ-adrenergic characteristics in rats were assessed biochemically by means of radioligand binding studies on pulmonary membranes and functionally using isolated tracheal spirals. It was found that: (1) In vivo treatment with both drugs induced a reduction of the number ofβ-adrenoceptors bound by³H-dihydroalprenolol (³H-DHA); however, tulobuterol also induced an increased affinity forβ-adrenoceptor binding. (2) Tulobuterol induced a significant increase in the sensitization of tracheal smooth muscle, facilitating the relaxation of airway smooth muscle. The inhibition of³H-DHA binding with the three drugs was best fit in a two-binding site model, showing high- and low-affinity binding sites. The high-affinity sites had similar K _d values for terbutaline and tulobuterol (1.6 × 10⁻⁷ and 1.5 × 10⁻⁷, respectively). The high-affinity sites for salbutamol had a higher K _d value (9.4 × 10⁻⁷), suggesting a lower affinity. However, 64.6% and 61.7% of the total binding was inhibited with high affinity by tulobuterol and salbutamol, respectively, while 21.9% was inhibited with high affinity by terbutaline. Therefore, from the ratio of high- and low-affinity binding sites and the K _d values of the high-affinity binding sites, tulobuterol appeared the most potent drug with respect to binding to theβ ₂-adrenoceptor. Also, the coupling of the drug-receptor complex to the adenylate cyclase system and theβ ₂ selectivity of the drug were established. Theseβ ₂-agonistic properties of tulobuterol show the profile of a drug that may prove to be very useful in the management of obstructive lung disease.     

Acute and long-term effectiveness of tulobuterol inhaler,a newβ 2-agonist,in the treatment of asthma

Two separate studies were conducted to evaluate the efficacy and safety of tulobuterol and the development of tachyphylaxis, if any, after prolonged use. The first, a double blind, crossover study, compared the efficacy and safety of tulobuterol aerosol 400 μg tid and salbutamol aerosol 200 μg tid in 38 patients with reversible obstructive airways disease. Each study period lasted 4 weeks, separated by a one week washout period. Evaluation of efficacy was performed on day 1 by monitoring spirometric values up to 6 hours postdosing. Additionally, changes in baseline pulmonary function were evaluated by measuring FEV₁, FVC and PEFR at each weekly visit. Twenty-nine patients were evaluable. Tulobuterol was shown to be as effective as salbutamol in onset, peak, and duration of response. Mean increases in FEV₁ after tulobuterol ranged from 22% at 5 minutes postdose to 30% at 1 hour postdose; a clinically significant mean increase of 24% was recorded after 3 hours. In comparison, mean increases for salbutamol were 24% at 5 minutes postdose and 31% at 1 hour postdose; after 3 hours the mean increase was 21%. Statistically significantly greater increases in mean baseline FEV₁ were recorded in favor of tulobuterol. Following 2 weeks of each treatment, tulobuterol showed a mean increase of 14%, compared to a mean postsalbutamol increase of 12%. After 4 weeks, differences were again statistically significant, with tulobuterol showing a mean increase in baseline FEV₁ of 17% compared to 3% for salbutamol. Tulobuterol treatment was associated with smaller changes in blood pressure and pulse rate than salbutamol. Furthermore, it was associated with fewer side effects, and both the investigator and the patients favored tulobuterol in their global evaluations. In a second, separate long-term open study, 64 patients with reversible airways obstruction were treated with tulobuterol metered dose (400μg qid) inhaler. Monthly spirometric evaluations demonstrated a continually increasing predose FEV₁ of up to 11.5% in one study group (N = 45; treated for 6 months) and up to 17.8% in a second group (N = 15; treated for an additional 6 months). In addition to improved baseline pulmonary function, postdose responses were significantly elevated. Measurements taken up to 6 hours post-tulobuterol at the final study visit were similar to those obtained at the start of the study and indicated that tachyphylaxis did not develop. Diary data showed improvement in daily PEFR and a significant reduction in pulmonary symptoms, with the number of symptom-free days tending to increase throughout the study. Although most patients were taking concomitant medication such as theophylline and beclomethasone, side effects were noted in only 4 patients, and cardiovascular parameters were minimally affected. Global assessment at the end of the study indicated that 60–70% of the patients showed improvement.     

Electrophysiological effects mediated by the stimulation of cardiac β2-adrenoceptors with tulobuterol

Summary We studied the electrophysiological effects of the specific ₂-agonist tulobuterol in the guinea-pig sinus node and in sheep cardiac Purkinje fibers. Stimulation of ₂-adrenoceptors by tulobuterol resulted in a slight increase in the rate of firing of the sinus node. In Purkinje fibers, however, automaticity was not affected up to concentrations of 10^–6 M. Consistently, tulobuterol (10^–8–10^–6 M) did not affect the pacemaker current studied under voltage-clamp conditions. In the same range of concentrations (10^–8–10^–6 M) tulobuterol dose-dependently increased the contractile force of driven Purkinje fibers. Tulobuterol, at a very high concentration (10^–5 M), had membrane depressant effects as demonstrated by the block of automaticity induced in the spontaneously beating Purkinje fibers and by the reduction of the maximum rate of depolarization in driven preparations.Our results suggest that stimulation of ₂-adrenoceptors with tulobuterol in sheep Purkinje fibers is associated with an inotropic rather than a chronotropic effect. On the whole, the data confirm the lack of cardiac side effects of tulobuterol.     

Polymorphism of the ADRB2 Gene and Response to Inhaled Beta- agonists in Children with Asthma: A Meta-analysis

Background. About 9% of children have asthma, corresponding to almost 6.8 million children in the USA and 1.1 million in the UK. Asthma exacerbations are the leading cause of pediatric emergency room visits and impose a large burden on the individual, family, and society. There is mounting evidence that therapeutic failure of inhaled beta-agonists is associated with polymorphisms of the β₂-adrenergic receptor gene (ADRB2); specifically, mutations leading to amino acid changes at positions 16 and 27, which alter down-regulation of the β₂-adrenergic receptor (β₂AR), induce resistance to the smooth-muscle relaxing effect of β₂-adrenergic agonists. Methods. We conducted a meta-analysis to examine the association between ADRB2 polymorphisms and the response to inhaled β₂-adrenergic agonists in children with asthma. We included all published studies until November 2008, in which asthmatic children underwent testing for acute bronchodilator response, defined as ≥ 15% improvement in forced expiratory volume in 1 second (FEV₁) and single nucleotide polymorphism (SNP) genotyping for positions 16 and/or 27 of the β₂AR. Individual and summary odds ratios were calculated using a random effects model. Results. We identified three case-control or family-based studies involving 960 asthmatic children (692 children with negative β₂-bronchodilator response, defined as < 15% improvement in FEV₁ and 268 children with positive bronchodilator response). We found a significant association between favorable therapeutic response to inhaled β₂-adrenergic agonists in asthmatic children and the Arg/Arg phenotype at position 16 of the β₂AR [OR = 1.77; 95% CI (1.01; 3.1); p = 0.029], compared with the Arg/Gly or Gly/Gly phenotypes. The beneficial effect of Arg at position 16 of the β₂AR was most pronounced in African-American asthmatic children [OR = 3.54; 95% CI (1.37, 9.13)]. There was no association between clinical response to β₂-agonists and polymorphism at amino acid position 27 of the β₂AR (OR = 1.04; 95% CI [0.76,1.42]). Conclusions. Failure of bronchodilator response to inhaled beta-agonists in asthmatic children is associated with the Gly allele (Arg/Gly and Gly/Gly genotypes) at position 16 of the β₂-adrenergic receptor. Genetic typing for β₂AR polymorphism may help identify children with drug-resistant asthma.     

Effects of a combined treatment theophylline and tulobuterol on nocturnal chronic asthma

The efficacy of a bronchodilator combination therapy (a slow-release xanthine derivative plus an oralβ ₂-mimetic—tulobuterol) in the treatment of nocturnal asthma attacks was compared to the efficacy of a monotherapy using a xanthine derivative alone.     

Action of tulobuterol and fenoterol on the mucociliary clearance

The influence of tulobuterol and fenoterol upon mucociliary clearance (mC) and airway obstruction was investigated in 8 patients with chronic obstructive bronchitis and two patients with chronic bronchial asthma. The lung function and mC measurements were repeated after a 1-week random oral treatment with 4 mg tulobuterol/day or 7.5 mg fenoterol/day in a double-blind cross-over design. Tulobuterol and fenoterol improved mC of the total, central and peripheral bronchial tree significantly in comparison to the pretreatment values (p less than 0.001) reaching, after beta 2-agonist therapy, values observed in normal subjects. In comparison to no treatment and pretreatment with oral fenoterol, tulobuterol protected slightly better from the inhalative provocation with 99mTc radioactive erythrocytes used to measure mC. Inhalative fenoterol was more efficient than oral fenoterol or tulobuterol to reverse the bronchospastic part of airway obstruction. No differences of mean daily peak flows, systolic and diastolic systemic blood pressure measurements and pulse rate were recorded during tulobuterol and fenoterol treatment. Both drugs were tolerated without side effects.     

Two-month comparative study of tulobuterol aerosol versus fenoterol aerosol in patients with chronic obstructive lung disease

In this two month, double-blind, crossover study, the efficacy and safety of tulobuterol aerosol (400μg qid) was compared to fenoterol aerosol (400μg qid) in patients with chronic obstructive lung disease. Thirty-six (36) adults with reversible bronchospasm were enrolled. All patients were evaluable. On set of response was within 5 minutes for both drugs. Mean increases in FEV₁ were greater after tulobuterol than fenoterol at every time interval. Increases peaked at 30–60 minutes postdose. Duration of response was longer after tulobuterol with mean FEV₁ remaining >15% over baseline for at least 6 hours postdose. Mean predose FEV₁ values were significantly greater after 2 and 4 weeks of tulobuterol treatment compared with fenoterol. Despite these large increases, changes in mean FEV₁ from predose to 1 hour postdose at these visits were not significantly different between treatment groups. Results of plethysmography testing also indicated greater improvement after tulobuterol. In addition, improvement in pulmonary symptoms was more pronounced during tulobuterol therapy. Small changes in mean blood pressure occurred, with greater changes after fenoterol than after tulobuterol. Changes in mean pulse rate were significantly greater following fenoterol administration. No adverse reactions were reported during tulobuterol treatment; however, one patient experienced severe tremor, tachycardia, and sweating during fenoterol treatment and withdrew from the study prematurely. The results in this study indicate that tulobuterol aerosol is more effective than fenoterol aerosol in the treatment of patients with chronic obstructive lung disease, with fewer cardiovascular effects and no adverse reactions.     

Clinical evaluation of tulobuterol patch in patients with mild or moderate persistent bronchial asthma-effects of long-term treatment on airway inflammation and hypersensitivity]

The tulobuterol transdermal therapeutic system (TTS) is the world's first commercially available transdermal preparation of tulobuterol, a beta-2 stimulant, that can maintain effective blood tulobuterol levels for 24 hours when applied once daily. In the present study, a total of 36 adult patients with mildly persistent (Step 2) or moderately persistent (Step 3) bronchial asthma 19 who were using inhalational steroids and 17 who were not used tulobuterol TTS for one year and underwent measurement of peak expiratory flow (PEF) once daily. Peripheral eosinophil count, serum eosinophil cationic protein (ECP) level and airway responsiveness (Dmin) were evaluated at 6 months and 1 year after the start of the study. PEF exhibited significant improvements at 6 months and 1 year in patients treated with or without inhalational steroids, while serum ECP was improved significantly only in the patients on inhalational steroids. Patients not using inhalational steroids exhibited no significant exacerbation of Dmin at either 6 months or 1 year: One-year treatment with tulobuterol TTS did not appear to cause tachyphylaxis. The significant improvements in Dmin at 6 months and 1 year in the patients using inhalational steroids suggested that inhalational steroids offer beneficial effects in controlling airway inflammation. Tulobuterol TTS is considered quite beneficial in improving quality of life (QOL) in patients with bronchial asthma because its incidence of adverse effects including palpitations and shivering is significantly lower than those of oral preparations, because of its remarkable improvement of pulmonary function and symptoms of airway obstruction without increasing airway responsiveness even after repeated use, and because it is simple to use and offers excellent clinical efficacy.     

Improvement of pulmonary function and dyspnea by tiotropium in COPD patients using a transdermal beta(2)-agonist

BACKGROUND: A combination of bronchodilators may be effective in the treatment of chronic obstructive pulmonary disease (COPD). We examined the effect of adding a long-acting anti-cholinergic agent (tiotropium) to a transdermal-type beta(2)-agonist (tulobuterol) on dyspnea as well as pulmonary function. METHODS: In a multicentre, randomized, parallel design study, 60 COPD patients treated with the transdermal beta(2)-agonist tulobuterol were divided into a tiotropium added group (Tulo+Tio group, n=40) or transdermal beta(2)-agonist tulobuterol alone group (Tulo group, n=20), and then treated for 4 weeks after a 2 week run-in period. Pulmonary function and a dyspnea (Medical Research Council (MRC)) scale were assessed before and after the treatment. Daily peak expiratory flow (PEF) monitoring was also performed. RESULTS: After 4 weeks, the Tulo+Tio group showed a significant increase in pulmonary function compared with the Tulo group; DeltaFVC (0.31+/-0.06 L vs. 0.06+/-0.05 L, p< 0.01), DeltaFEV(1) (0.15+/-0.03 L vs. -0.02+/-0.02 L, p<0.0001), and DeltaPEF (41.0+/-5.1 L/min vs. 0.5+/-3.5 L/min, p<0.0001). The MRC dyspnea scale was also significantly improved in Tulo+Tio, but not in Tulo group. CONCLUSION: These results suggest that tiotropium caused a significant improvement in both pulmonary function and dyspnea in COPD patients already treated with the transdermal beta(2)-agonist tulobuterol.     

Risk/benefit ratio of long-term treatment withβ 2-adrenoceptor agonists

Optimal control of chronic obstructive airway disorders is usually achieved with therapy based onβ ₂-adrenoceptor agonist administration. Aerosols are highly effective, have few side effects, allow for fine adjustment of dosage to titrate symptoms, and result in reduction in hyperreactivity. Equivalent bronchodilating doses of oral agents cause side effects that limit acceptability. With oral agents, cardiohemodynamic disturbances are usually minor, while tremor and restlessness diminish with continued drug use. In chronic regimens, an aerosolβ ₂-adrenergic agent should be chosen whose overall incidence of side effects is less than 5%, and an oral agent that produces no more than a 10% incidence of tremor. Suboptimal oral dosages in combination with maximal dosages ofβ ₂-agonist aerosol, with or without other bronchodilator drugs, are advisable for chronic therapy. An optimal risk/benefit ratio with broxaterol therapy will probably be achieved by using an aerosol-oral combination. Thus, broxaterol, a newβ ₂-agent, should be studied further to determine its value in chronic bronchospastic disorders.     

Bronchial asthma and the role ofβ 2-agonists

Asthma is defined as reversible airflow obstruction; the mechanism for this airflow obstruction is considered to be caused by a combination of an inflammatory process leading to a thickened edematous airway lining and bronchial smooth muscle constriction. The identification of specificβ-receptors in the autonomic system led to the development in the early 1960s of selectiveβ ₂-agonists with their precise effects on the bronchial smooth muscle without direct action on cardiac muscle. The earlyβ ₂-agonists such as salbutamol have a comparatively short bronchodilator action but a rapid onset of action, making them useful as “rescue” bronchodilators. Regularβ ₂-agonists alone may mask the underlying pathogenesis of asthma and may be associated with tachyphylaxis or rebound bronchial hyperreactivity. The observation that a thickened airway lining may lead to disproportionate increases in airways resistance with small changes in bronchial muscle shortening suggestsβ ₂-agonists should be given in conjunction with anti-inflammatory therapy. With their long duration of action but slow onset the newβ ₂-agonists may have a role in prophylaxis of asthma rather than rescue bronchodilation.     

A literature review of the evidence that a 12% improvement in FEV1 is an appropriate cut-off for children

Introduction: A well-performed spirometry, using a change in forced expiratory volume in one second (FEV₁) after albuterol, is commonly used to support the likelihood of an asthma diagnosis. The current standard, accepted by the 2007 National Heart Lung and Blood Institute Asthma Expert Panel Report-3 (EPR-3) guidelines, is a 12% improvement in the FEV₁ after a bronchodilator. Objective: We sought to determine whether existing studies support or refute using a 12% improvement as a significant change in FEV₁ in children and adolescents. Data sources: We reviewed the literature of children and adolescents using Medline searches to discover pertinent population studies and comparative studies that included FEV₁ measurements. Result: The majority of the discovered studies suggest a less stringent improvement in FEV₁ in children might be applicable. Conclusion: Supported by the published literature, we suggest an alternative interpretive strategy of expressing the results of a spirometry measurement when a diagnosis of asthma in a child is being considered using a bronchodilator response.     

达托霉素对2679株革兰阳性球菌外抗菌活性的研究

目的 研究达托霉素等抗菌药物对2679株革兰阳球菌的体外抗菌活性.方法 收集2010年1月-2011年12月9个城市17家教学医院临床分离的2679株非重复革兰阳性球菌.采用微量肉汤稀释法测定的达托霉素最低抑菌浓度(MIC),用琼脂稀释法测定其他抗菌药物的MIC值,用WHONET5.6软件进行药敏数据统计分析.结果 耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRSCoN)检出率分别为45.8％和84.2％,MRSA对复方磺胺甲(噁)唑和氯霉素的敏感率分别为93.1％和85.5％,对红霉素、四环素、克林霉素和利福平的敏感率分别为13.8％、26.6％、63.2％、50.0％,对达托霉素、万古霉素和利奈唑胺的敏感率均为100.0％,MRSCoN对达托霉素、万古霉素和利奈唑胺的敏感率均为100.0％,达托霉素对于MRSA和MRSCoN的MIC50和MIC90均为0.5 mg/L.513株肠球菌对于高水平庆大霉素耐药率为56.9％,氯霉素和四环素的敏感率分别为76.0％和44.1％,对替加环素和达托霉素敏感率均达100.0％,达托霉素对于其中17株耐万古霉素肠球菌(V RE)的MIC50和MIC90均为2 mg/L.肺炎链球菌和β-溶血链球菌对于达托霉素的敏感率均为100.0％,按口服青霉素折点判读,青霉素不敏感的肺炎链球菌(PNSSP)的比例为63.1％.达托霉素对于PNSSP的MIC50和MIC90分别是0.125 mg/L和0.25 mg/L.达托霉素对于β-溶血链球菌MIC50和MIC90分别是0.008 mg/L和0.032 mg/L.结论 达托霉素对临床常见革兰阳性球菌具有较好的抗菌活性,包括多重耐药菌,是治疗革兰阳性菌特别是耐药菌感染的很好选择.     

Patient factors that predict failure of omeprazole, clarithromycin, and tinidazole to eradicateHelicobacter pylori

Omeprazole (20mg od/b.d.), clarithromycin (250mg b.d.) and tinidazole (500mg b.d. for 7 days) [OCT] is an effective regimen againstHelicobacter pylori. However, treatment fails in 5%–10% of patients and the reasons for this are not clear. We investigated patient factors that independently predicted failure of this regimen.H. pylori-positive patients were prescribed OCT and the success of treatment was evaluated by the¹³C-urea breath test at least 4 weeks after completion of therapy. Patients were prospectively interviewed on past medical history of peptic ulcer and H₂-receptor antagonist (H₂RA) pre-treatment, smoking history, and alcohol intake. Data were also collected on age, gender, and endoscopic diagnosis to determine factors predicting failure of OCT.H. pylori eradication was achieved in 238 of 273 patients [87%–95% confidence intervals (CI), 83%–91%]. Age, alcohol intake, past medical history of peptic ulcer and peptic ulcer at endoscopy were not independently associated with treatment failure.H. pylori eradication with OCT was less successful in women (P=0.02), in patients who had received H₂RA pre-treatment (P=0.02), and in smokers (P=0.02) when evaluated by multiple logistic regression. These findings indicate that OCT is less effective in smokers and in patients who receive H₂RA pre-treatment suggesting that these agents should be avoided, if possible, before the patient commences therapy.H. pylori eradication was less successful in women; this result needs further evaluation.     

Fructose 2,6-bisphosphate metabolism in Ehrlich ascites tumour cells

Cancer cell energy metabolism is characterized by a high glycolytic rate, which is maintained under aerobic conditions. In Ehrlich ascites tumour cells, the concentration of fructose 2,6-bisphosphate (Fru-2,6-P ₂), the powerful activator of 6-phosphofructo-1-kinase, is tenfold increased. The bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFK-2/FBPase-2), synthesizing and degrading Fru-2,6-P ₂, was characterized. The molecular mass is 120 kDa. The dependence of PFK-2 activity on the substrate concentrations is hyperbolic (K _m for Fru-6-P=0.09 mM;K _m for ATP=0.7 mM), while the dependence of the FBPase-2 activity on the concentrations of Fru-2,6-P ₂ is sigmoidal (K _0.5 for Fru-2,6-P ₂=4M). The PFK-2/FBPase-2 activity ratio is 1. PFK-2 activity is inhibited by citrate (I _0.5=0.17 mM) and phosphoenolpyruvate (I _0.5=0.08 mM) but only weakly by glycerol 3-phosphate (I _0.5=1.57 mM). In contrast to the liver enzyme, the activity of tumour PFK-2/FBPase-2 is not influenced by the action of cAMP-dependent protein kinase. The kinetic properties as well as ion-exchange chromatography pattern differ from their normal counterparts in liver and muscle. The properties are likely to contribute to the maintenance of the high glycolytic rate in these tumour cells.Abbreviations Fru-2,6-P ₂ fructose 2,6-bisphosphate - FBPase-2 fructose-2,6-bisphosphatase - PFK-2 6-phosphofructo-2-kinase - Fru-6-P fructose 6-phosphate     

Inhibition of platelet activation by peptide analogs of the β3-intracellular domain of platelet integrin αIIbβ3 conjugated to the cell-penetrating peptide Tat(48–60)

Activation of the platelet integrin-receptor α_IIbβ₃ is the final pathway of platelet aggregation, regardless of the initiating stimulus. Many studies suggest that there are several cytoplasmic proteins such as talin and β₃-endonexin that bind to N⁷⁴⁴PLY⁷⁴⁷ and N⁷⁵⁶ITY⁷⁵⁹ motif of the β₃ cytoplasmic tail and play the major role in the receptor activation. In this study, we investigated the role of the membrane distal region of human β₃ cytoplasmic tail and specifically the N⁷⁴³NPLYKEA⁷⁵⁰ and T⁷⁵⁵NITYRGT⁷⁶² sequence that contains an NXXY motif, in platelet aggregation, secretion, α_IIbβ₃ activation (PAC-1 binding) and fibrinogen binding. We synthesized two peptides corresponding to the above sequences as well as their conjugates with the Tat(48–60) cell-penetrating peptide. The capability of conjugates to penetrate the platelet membrane was investigated with confocal laser scanning microscopy using carboxyfluorescein (CF)-labeled peptides. Our results showed that the conjugated with the Tat(48–60) sequence peptides penetrate the platelet membrane and inhibit platelet aggregation in both PRP and washed platelets in a dose-dependent manner. The Tat-β₃743–750 conjugate exhibited similar inhibitory activity in PRP and in washed platelets whereas the Tat-β₃755–762 conjugate was more potent inhibitor of aggregation in washed platelets than in PRP. Both conjugated peptides were also able to inhibit P-selectin membrane expression as well as PAC-1 and fibrinogen binding to the platelets, the Tat-β₃755–762 conjugate being more potent than Tat-β₃743–750. The Tat(48–60) peptide and the peptides β₃743–750 and β₃755–762, which were not conjugated to the Tat(48–60) sequence, did not exhibit any inhibitory effect on the above parameters. In conclusion, the present study shows for the first time that the peptide analogs of the intracellular domain of the β₃ subunit β₃743–750 and β₃755–762 conjugated to the cell-penetrating peptide Tat(48–60) are capable of penetrating the platelet membrane and expressing biological activity by inhibiting the activation of α_IIbβ₃, the fibrinogen binding to the activated receptor as well as platelet aggregation. Further studies are necessary to support whether such conjugated peptides may be useful tools for the development of potent antiplatelet agents acting intracellularly through the platelet integrin α_IIbβ₃.     

Bronchodilatation Effects of a Small Volume Spacer Used with a Metered-Dose Inhaler

Background and objective. In an effort to improve the delivery of drugs to the lungs, various spacer devices have been developed to attach to metered-dose inhalers (MDIs). The aim of the study was to determine whether use of a small volume tube spacer with MDI is associated with better bronchodilatation. Methods. We assessed bronchodilatation by measuring forced expiratory volume in 1 second (FEV₁) before and after inhalation of fenoterol 0.4 mg (2 puffs) delivered by using a MDI in four different ways: with or without a spacer alone or with a mouth rinse of 100 mL of water immediately after inhalation with or without a spacer. Results. A total of 303 patients who had a positive bronchodilator test were studied. There was no significant difference in the ΔFEV₁ (mL or %) with or without a spacer (MDI + spacer vs. MDI, mean ± SD, 365.1 ± 146.5 mL vs. 356.3 ± 131.1 mL, p = 0.696; and 21.4 ± 9.4% vs. 21.4 ± 9.5%, p = 0.968, respectively). When patients rinsed their mouth after inhalation, bronchodilatation was significantly less in those using an MDI alone compared with MDI + spacer (302.6 ± 116.5 mL vs. 367.6 ± 128.3 mL, p = 0.002; and 18.0% ± 7.9% vs. 21.7% ± 9.5%, p = 0.013, respectively). Conclusions. When patients correctly use an MDI, addition of a spacer does not significantly improve bronchodilatation. However, if the mouth is rinsed after inhalation, a spacer does yield better bronchodilatation. Our results suggest that systemic effects from bronchodilator inhalation may not be negligible.     

Differing Expression of Cytokines and Tumor Markers in Combined Pulmonary Fibrosis and Emphysema Compared to Emphysema and Pulmonary Fibrosis

This study aimed to explore the different pathogeneses of combined pulmonary fibrosis and emphysema (CPFE) from emphysema and pulmonary fibrosis. The levels of transforming growth factor-β₁ (TGF-β₁), vascular endothelial growth factor (VEGF), Krebs Von Den Lungen-6 (KL-6), matrix metalloproteinase-9 (MMP-9), tissue inhibitors of metalloproteinases-1 (TIMP-1), cytokeratin 19 fragment (CYFRA21-1), squamous cell carcinoma antigen (SCC), and the telomerase activity in peripheral blood were measured in 38 CPFE patients, 50 pulmonary emphysema patients, and 34 idiopathic pulmonary fibrosis (IPF) patients. The results demonstrated that the levels of VEGF and TGF-β₁ in IPF patients were significantly higher than those in emphysema patients (p < 0.05), and no significant differences were detected between CPFE patients and other two groups (p > 0.05). The levels of KL-6 and CYFRA21-1 in IPF patients were significantly higher than those in emphysema and CPFE patients (p < 0.05), and the latter had the similar levels (p > 0.05). Among the three groups, the levels of SCC, MMP-9, TIMP-1, MMP-9/TIMP-1 ratio, and telomerase activity were not different (p > 0.05). Our study showed that VEGF, TGF-β₁, KL-6, and CYFRA21-1 may play a role in the pathogenesis of pulmonary fibrosis. The lower levels of KL-6 and CYFRA21-1 in CPFE patients may be one of the reasons why these patients develop emphysema on the basis of fibrosis.     

Clinical Efficacy and Safety of Transdermal Tulobuterol in the Treatment of Stable COPD: An Open-Label Comparison with Inhaled Salmeterol

Background: Long-acting bronchodilators are recommended for the management of stable COPD to relieve symptoms and improve quality of life. The tulobuterol patch (Hokunalin®) is a transdermal patch preparation of the β₂-adrenoceptor agonist (β₂-agonist) tulobuterol designed to yield sustained β₂-agonistic effects for 24 hours when applied once daily. Objective: To compare the effectiveness of tulobuterol patch and inhaled salmeterol (Serevent® Diskus) in the treatment of stable COPD. Study design: Clinically stable COPD patients (age ≥40 years, postbronchodilator FEV₁/FVC <70%, and postbronchodilator FEV₁ <80% predicted) were enrolled in a multicenter, open-label randomized study. After a 2-week run-in period, patients were administered either tulobuterol (2mg once-daily applied as a patch) or salmeterol (50μg per inhalation, twice a day) for 12 weeks. Results: Data for 92 patients (46 each for each treatment group) were analyzed. There were no significant differences in baseline characteristics in the tulobuterol versus salmeterol groups: age, 69.2 ± 7.4 vs 71.6 ± 7.3 years; male, 91% versus 96%; and patients with stage II (III) COPD, 32.6% (67.4%) versus 50% (50%). FEV₁, FVC, and PEF improved during treatment in both groups compared with baseline, with no significant between group differences. The total St George’s Respiratory Questionnaire (SGRQ) score was significantly improved relative to baseline in the tulobuterol group at 8 weeks (?4.7 units [U]), but not in the salmeterol group at all timepoints. Domain analysis of the SGRQ scores revealed significant improvement in the symptom score relative to baseline in the tulobuterol group at weeks 4 (?6.9U), 8 (?12.0U), and 12 (?11.7U), but not in the salmeterol group in any of the domains tested. Medical Research Council dyspnea scale score improved during treatment in both groups, with no significant differences between groups. Compliance with the treatment regimen was significantly better in the tulobuterol than in the salmeterol group (98.5% vs 94.1%; p < 0.05). Conclusion: These findings indicate that once-daily transdermal sustained-release tulobuterol is as effective or better than the inhaled long-acting β₂-agonist salmeterol in the management of stable COPD, with significant effects on quality of life.