左氧氟沙星滴眼液不同给药方式患者房水与血浆药物浓度的差异

目的探讨左氧氟沙星滴眼液经过不同的给药方式后,对房水及血浆中药物浓度的影响。方法纳入预行超声乳化术的白内障患者90例,随机分为A、B组,A组又随机分为3个亚组,每组10例,A1组:术前1 d给药,6次/d,A2组:术前2 d给药,4次/d,A3组:术前3 d给药,4次/d。B组给药方式为术前3 d给药,4次/d,并于手术当日分别在术前7.5,15,30,45,60和120 min单一剂量给药。术中抽取100μl房水置于EP管中,并同时抽取5 ml静脉血,将静脉血离心,取上清液置于EP管中,放置-80℃冻存,采用高效液相色谱质谱串联质谱技术(HPLC-MS/MS)测定房水及血浆左氧氟沙星浓度。结果 A1,A2及A3组房水及血浆中左氧氟沙星浓度组间差异均无统计学意义(P=0.281,P=0.478)。B组单一剂量给药后房水中药物浓度逐渐上升,45.0 min时达到最高值,之后逐渐下降,且45 min与7.5,15.0,30.0,60.0及120.0 min时药物浓度的差异均有统计学意义(P=0.000,0.000,0.010,0.012,0.029);血浆中药物浓度逐渐上升但不明显,在45.0 min时药物浓度达到最高,之后逐渐下降,45.0 min时血浆药物浓度与7.5,30.0,60.0及120.0 min差异均有统计学意义(P=0.010,0.033,0.05,0.016);且血浆药物浓度远远低于房水药物浓度(均P0.05)。结论白内障术前1 d应用左氧氟沙星滴眼液,6次/d的方式效果最佳。左氧氟沙星滴眼液单一剂量点眼后45 min房水中药物浓度达到最高值,血浆药物浓度远远低于房水药物浓度。     

盐酸左氧氟沙星在大鼠胰腺的药代动力学研究

目的 研究盐酸左氧氟沙星在大鼠胰腺组织的药代动力学.方法 采用微透析技术对大鼠胰腺组织和血液进行同步取样,联合反相高效液相色谱实时检测胰腺组织和血液中盐酸左氧氟沙星的浓度变化,所得药物浓度数据用WinNonlin软件处理.结果 大鼠血液中的游离左氧氟沙星浓度在给药后10 min时最高,为(65.23±12.9)μg/ml,胰腺组织在20 min到达峰浓度(30.56±3.22)μg/ml,然后持续下降;给药后20 min时胰腺组织的药物浓度开始高于血清,并持续至100 min,然后下降,两者浓度始终保持接近.血液、胰腺的药时曲线下面积分别为(2914.38±205.73)min·μg~(-1)·ml~(-1)和(2465.11±258.56)min·μg~(-1)·ml~(-1).结论 微透析采样技术联合反相高效液相色谱检测方法可以准确客观地反映药物在组织和血液中的药代动力学特点,盐酸左氧氟沙星具有较高的胰腺组织药物浓度.     

中国健康受试者多剂口服吉米沙星的药代动力学及药效学研究

目的 研究中国健康受试者对吉米沙星的临床药代动力学(PK)和药效学(PD),为优化临床给药方案提供依据.方法 随机、双盲临床试验中,招募20名健康受试者按1∶1比例分为给药组或对照组,分别予以多剂口服320 mg吉米沙星或安慰剂.高效液相色谱荧光法测定受试者血浆和尿液的药物浓度.采用微量稀释法测定吉米沙星对190株社区获得性肺炎常见临床分离菌株的最低抑菌浓度(MIC).以给药后24 h血浆药物浓度时间曲线下面积(AUC0～24h)与MIC的比值(fAUC0～24 h/MIC)和药物峰浓度(Cmax)与MIC的比值(fCmax/MIC)为指标(靶值为25和5),评价吉米沙星的PK和PD特性,并采用蒙特卡洛模拟评价吉米沙星320 mg 1次/d在稳态血药浓度下对上述细菌的累积反应百分比(CFR)及不同MIC水平下的PD达标概率.采用F检验对各组数据作方差齐性检验,采用t检验分析各组间数据.结果 健康受试者多剂口服吉米沙星320 mg 1次/d连续7d给药后的首剂和末剂Cmax分别为(1.55±0.32)和(1.57±0.31) μg/mL,AUC0～24h分别为(7.91±1.52)和(8.91±1.15)h·μg·mL-1,积蓄因子为1.13±0.05.吉米沙星在受试者体内的PK符合二房室模型,分布相和消除相半衰期分别为(0.64±0.17)和(7.10±2.10)h.首剂和末剂给药后24 h平均累积尿排出率分别达34.83％和38.95％.PD研究显示,吉米沙星对肺炎链球菌和卡他莫拉菌的MIC90分别为0.25和0.125 mg/L,对流感嗜血杆菌的MIC90为2 mg/L,而肺炎克雷伯菌和甲氧西林耐药金黄色葡萄球菌对吉米沙星大部分呈现耐药( MIC90＞32 mg/L).当吉米沙星对细菌的MIC值≤0.06mg/L时,吉米沙星320mg 1次/d连续7d给药方案达到fAUC0～24h/MIC和fCmax/MIC的药效学达标概率值均接近100％.结论 中国健康受试者单剂口服吉米沙星320 mg后吸收迅速,多剂给药后第3天达到稳态血药浓度,连续7d给药后有轻度蓄积.PK/PD分析显示,对该药敏感的社区获得性肺炎和慢性阻塞性肺病急性加重者预期可获得良好的临床和细菌学疗效.     

左旋咪唑预防钩虫幼虫经肤感染的研究

本文报告左旋咪唑外用预防钩虫感染的持久性的机理。钩虫幼虫经涂有0.5％或1.5％左旋咪唑(下称左剂)小鼠皮肤的浸液处理后1周或3周内,丧失侵肤能力。鼠肤涂1.5％~3H—左剂后3d内,皮肤含药量迅速下降,以后速度变慢,渐趋稳定,4～5周后,尚可测到微量。药物集中在涂药局部皮肤,药液浓度高者,皮肤含药量也高,皮肤给药后局部药浓度远高于口服给药。提示左剂皮肤给药的代谢转化速率较口服给药的为低,保持生物活性的时间也较长。     

左氧氟沙星不同服用方法对耐多药肺结核的疗效观察

左氧氟沙星(V)最主要的药代动力学参数是血清峰浓度(Cmax)与药物—时间曲线下面积(AUC)，它属于浓度依赖性抗生素，每天只需足量给药1次，无需多剂量给药。但在多家国产左氧氟沙星药品说明书的“用法与用量”项下标明。“静脉注射，成人每天400mg，分2次静脉滴注”或“口服，成人每次0．1～0．2g，每天2次”。部分医生在用左氧氟     

20例结核性脑膜炎血、脑脊液左氧氟沙星浓度测定

目的探讨左氧氟沙星能否透过结脑患者血脑屏障。方法 20例结核性脑膜炎患者提供血和脑脊液标本,采用HPLC法测定血浆和脑脊液中的药物浓度。结果 20例结脑患者口服400 mg左氧氟沙星2 h、4 h、6 h后,其血清平均药物浓度（μg/m l）分别为5.33、5.29、3.72,脑脊液左氧氟沙星平均药物浓度分别为1.38、1.77、2.19,2 h、4 h、6 h脑脊液/血分别为0.258、0.334、0.588。结论 400 mg左氧氟沙星能透过结脑患者血脑屏障,在脑脊液中浓度能达到抑制结核分枝杆菌浓度。     

替比夫定的药代动力学研究

目的评价中国健康志愿者单次口服不同剂量替比夫定的药代动力学特征以及多次给药后的稳态血浆药代动力学。方法42名年龄在18～40岁的健康志愿者,男32名,女10名,随机分配到200、400、600、800mg 4个剂量组。其中600mg剂量组受试者接受单剂量和多剂量的研究。多剂量每日给药,持续8d。采用HPLC-MS/MS法测定给药前和给药后不同时间替比夫定的主血浆、尿液药物浓度,并据此计算药代动力学参数。结果在单次口服200、400、600、800mg片剂后,受试者的达峰时间分别为2．50、2．00、2．00h和2．50h；半衰期的平均值分别为(43．3±15．2)h、(49．1±14．4)h、(39．4±12．1)h和(46．7±20．8)h；血药达峰浓度平均值分别为(1 753．2±389．0)ng/ml、(2 586．7±871．4)ng/ml、(3 703．6±1 219．0)ng/ml和(3 454．6±953．9)ng/ml；曲线下面积的平均值分别为(12 843．2±2 925．6)ng·h ~(1·)ml~1、(22 948．9±5 721．0)ng·~(1·)ml~1、(26 440．5±8 938．1)ng·h ~(1·)ml~1以及(28 820．9±7 912．9)ng·h ~(1·)ml~1；血浆清除率(600mg)为(6 545．6±1 504．4)ml/h；多次给药后的稳态药代动力学研究结果显示,在600mg/d的给药剂量下,连续给药8d后,平均稳态药时曲线下面积为(26 123．9±7 196．3)ng·h ~(1·)ml~1,平均血药浓度为(1 088．5±299．8)ng/ml,血药达峰浓度和曲线下面积蓄积囚子分别为1．02±0．21和1．23±0．26。结论受试者口服替比夫定以后,吸收较为迅速,给药后的2～3h即达到峰值。在200mg至800mg剂量范围内,血浆中替比夫定的药代动力学参数均呈现出一定的规律。替比夫定在受试者体内有轻微蓄积。     

Ranitidine——一种新的H_2-受体拮抗剂

Ranitidine(氨甲呋喃衍化物)是一种强烈的竞争性H_2-受体拮抗剂,对H_1-受体及乙酰胆碱受体无何作用。它可抑制组织胺、五肽胃泌素或试餐对实验动物刺激的胃酸分泌,口服或肠道外给药均有效,作用较甲氰咪胍强4～5倍以上。本文报道采用该药在人体进行的两项研究结果,并加以讨论。自愿受试者为7名健康成年男性。研究分两项进行。每次实验均于禁食一夜后次日上午开始。第一项实验受试者6名,口服与静脉注射盐酸Ranitidine 20、40及80mg(基质),除1名受试者未接受80mg的静脉注射外,其他受试者均分次接受口服及静脉注射(溶于20ml生理盐水中,取肘前静脉,2分钟注射毕)。给药前和给药后24小时内定时采取血、尿标本,以计算药物在血中的半减期和有效率,并作多项血液学和临床生化     

肺结核合并糖尿病对抗结核药物血药浓度的影响

目的 研究肺结核合并糖尿病对吡嗪酰胺、左氧氟沙星的血药峰浓度的影响,为糖尿病合并肺结核患者用药提供理论依据。方法 以随机数字表法选取糖尿病合并肺结核的患者为观察组（左氧氟沙星组30例,吡嗪酰胺组20例）,单纯肺结核为对照组（左氧氟沙星组30例,吡嗪酰胺组20例）,两组分别服用抗结核药物吡嗪酰胺、左氧氟沙星,在服药7 d后,用高效液相色谱法（HPLC）测定患者抗结核药物的血药峰浓度,两组间进行对比,采用SPSS 13.0软件进行统计分析。结果 左氧氟沙星在糖尿病合并肺结核组的血药峰浓度较单纯肺结核组明显升高［分别为（8.03±2.60）μg/ml和(6.66±1.76) μg/ml,t=2.39,P=0.02］;而吡嗪酰胺在两组间差异无统计学意义［分别为(14.24±4.79)μg/ml和(14.86±5.74)μg/ml,t=0.37,P=0.71］。结论 左氧氟沙星在糖尿病合并肺结核患者体内的血药峰浓度较单纯肺结核患者明显升高,提示糖尿病患者在应用左氧氟沙星时应该注意其血药峰浓度。有无糖尿病对吡嗪酰胺在体内血药浓度没有影响。     

胺碘酮与其代谢物去乙基胺碘酮的比较研究

目的　研究健康受试者单剂和连续口服胺碘酮后原形药物和活性代谢物去乙基胺碘酮的药代动力学特点及相互关系。方法　 36例健康男性受试者分两组。单剂量组 2 0例 ,服药 80 0mg/次 ;多剂量组 1 6例 ,服药 60 0～ 80 0mg/d ,连续服药至停药标准。采用反相HPLC方法同时测定受试者胺碘酮和去乙基胺碘酮血药浓度 ,并计算药代动力学参数。主要药代动力学参数比较采用方差分析。结果　 (1 )单剂量组 :胺碘酮和去乙基胺碘酮的达峰时间 (Tmax)分别为 (5 2± 1 5)h和 (8 6± 3 2 )h ,峰浓度 (Cmax)分别为 (0 764± 0 383)mg/L和 (0 1 2 6± 0 0 71 )mg/L ,0至 48h取样的血药浓度 时间曲线下面积 (AUC0 4 8)分别为 (1 0 593± 4 977)mg·h·L- 1 和 (3 936± 1 2 88)mg·h·L- 1 ;(2 )多剂量组 :胺碘酮和去乙基胺碘酮间Tmax和末端消除速率常数 (Ke)差异无显著性 (P >0 0 5) ;其余药代动力学参数Cmax、Tmax、AUC0 4 8等两者之间差异有显著性 (P <0 0 1 )。口服两种负荷剂量后 ,代谢物的各药代动力学参数两组间差异无显著性。结论　无论是单剂或短期连续口服胺碘酮 ,其原形药物、去乙基胺碘酮均存在滞后作用 ,临床给药时应考虑原形药物及其代谢物累积药效的影响     

Airway drug pharmacokinetics via analysis of exhaled breath condensate

Although the airway surface is the anatomic target for many lung disease therapies, measuring drug concentrations and activities on these surfaces poses considerable challenges. We tested whether mass spectrometric analysis of exhaled breath condensate (EBC) could be utilized to non-invasively measure airway drug pharmacokinetics and predicted pharmacological activities.Mass spectrometric methods were developed to detect a novel epithelial sodium channel blocker (GS-9411/P-680), two metabolites, a chemically related internal standard, plus naturally occurring solutes including urea as a dilution marker. These methods were then applied to EBC and serum collected from four (Floridian) sheep before, during and after inhalation of nebulized GS-9411/P-680. Electrolyte content of EBC and serum was also assessed as a potential pharmacodynamic marker of drug activity. Airway surface concentrations of drug, metabolites, and electrolytes were calculated from EBC measures using EBC:serum urea based dilution factors.GS-9411/P-680 and its metabolites were quantifiable in the sheep EBC, with peak airway concentrations between 1.9 and 3.4 μM measured 1 h after inhalation. In serum, only Metabolite #1 was quantifiable, with peak concentrations ∼60-fold lower than those in the airway (45 nM at 1 h). EBC electrolyte concentrations suggested a pharmacological effect; but this effect was not statistical significant.Analysis of EBC collected during an inhalation drug study provided a method for quantification of airway drug and metabolites via mass spectrometry. Application of this methodology could provide an important tool in development and testing of drugs for airways diseases.     

Standardization of exhaled breath condensate: effects of different de-aeration protocols on pH and H₂O₂ concentrations

Exhaled breath condensate (EBC) analysis is a non-invasive method to repeatedly evaluate airway inflammation. Dissolved carbon dioxide contributes to lowering EBC pH which is reversed by degassing with argon. Hypothetically, argon may also improve biomarker stability by removing reactive gases, since many markers are pH sensitive or easily oxidized. In this study, the influence of two degassing methods was assessed on (i) the volume of EBC, (ii) the EBC pH, and (iii) the concentration of H?O? in EBC. EBC was collected from 13 healthy subjects and 12 chronic obstructive pulmonary disease subjects over 20 min, then aliquoted and either left on ice or de-aerated with argon by bubbling or surface delivery at 400 ml min(-1) for 0 to 600 s, to quantify the EBC volume loss and the efficiency of pH equilibration. Biomarker stability was measured by H?O? concentration. Both degassing methods reached a pH equilibrium by 300 s. Bubbling reached pH equilibrium faster (60 s versus 300 s), while having significantly less EBC volume loss (bubbling 3.32 ± 1.31% versus surface 10.74 ± 1.46%, p < 0.0001). The H?O? concentration was higher in non-degassed samples (0.47 ± 0.18 μM, p = 0.017) but similar in the bubbling and surface degassed samples (0.30 ± 0.08 μM versus 0.31 ± 0.10 μM, p = 0.54). The optimal degassing methods were to bubble the aliquots with argon at 400 ml min(-1) for 60 s or surface degassing for 300 s. Both methods resulted in significantly less EBC volume loss than the commonly adopted method of bubbling for 10 min. There was a significant difference in the H?O? concentration between the degassed and the non-degassed samples.     

Adenosine in exhaled breath condensate in healthy volunteers and in patients with asthma.

Persistent airway inflammation may require the use of different markers for monitoring airway inflammation. In this study, the authors investigated whether adenosine, which may be produced in allergic inflammatory conditions, could be measured with good reproducibility in exhaled breath condensate (EBC), and whether its concentration was elevated in patients with asthma. EBC adenosine and exhaled nitric oxide (eNO), a noninvasive marker of asthmatic airway inflammation, were measured in 40 healthy volunteers and 43 patients with allergic bronchial asthma. Repeatability of adenosine measurement was checked in 20 pairs of samples collected from healthy control subjects. Adenosine was detectable in all EBC samples by the applied high-performance liquid chromatographic method. The mean difference between repeated measurements of adenosine was -0.1 nM and all differences were within the coefficient of repeatability. Adenosine concentration was higher in steroid-naive patients (n=23) compared with healthy control subjects and steroid-treated patients (n=20). In patients with worsening symptoms of asthma (n=23), adenosine concentration was elevated compared with those in a stable condition (n=20). Furthermore, adenosine concentrations were related to eNO levels in asthmatic patients. These results, showing good reproducibility of adenosine measurements and increased adenosine concentrations in steroid-naive patients and in patients with worsening of asthmatic symptoms, indicate that adenosine measurement in exhaled breath condensate might be an acceptable novel method to investigate the role of local production of adenosine in the airways.     

Apocynin reduces reactive oxygen species concentrations in exhaled breath condensate in asthmatics

Asthma is an inflammatory airway disease, and oxidative stress was proven to be involved in its pathogenesis. Apocynin effectively inhibits the main source of reactive oxygen species (ROS)-nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-by blocking its activation. The aim of this study was to investigate the effect of inhaled apocynin on ROS and RNS (reactive nitrogen species) concentration in 14 nonsmoking mild asthmatics. Effects of nebulized apocynin (0.5 mg/mL) were assessed in exhaled breath condensate (EBC) after 30, 60, and 120 minutes, and safety parameters have been analyzed. Apocynin significantly decreased H2O2 concentration in EBC in comparison with placebo after 60 and 120 minutes. Moreover, apocynin significantly reduced NO(-2) concentration 30 and 60 minutes after nebulization and caused a significant decrease of NO(-3) concentration in EBC 60 and 120 minutes after administration, comparing with placebo. No adverse events have been observed throughout the study. This research confirmed anti-inflammatory properties of nebulized apocynin, which might be an effective and safe drug in bronchial asthma.     

Exhaled breath condensate pH in infants and children with acute and recurrent wheezy bronchitis

The analysis of exhaled breath condensate (EBC) is a promising new method to measure airway inflammation. So far only limited data exist about methodological issues of EBC sampling in infants and young children. We evaluated 18 children with acute wheezy bronchitis (median age 24.3 months (min-max: 4-89.9)), 54 children with recurrent wheezy bronchitis (median age 52.5 months (7.2-94.8)), and 32 healthy controls (median age 49.6 months (25.3-67.8)). EBC was sampled with a modified commercially available EBC-sampler, pH was measured after deaeration. EBC volume was significantly correlated to age (r = 0.56, P < 0.001). EBC pH was significantly decreased in all patients compared to the healthy controls (acute wheezy bronchitis 7.87 (7.16-8.19), P = 0.003, recurrent wheezy bronchitis 7.86 (6.95-8.39), P = 0.002, and healthy controls 8.04 (7.81-8.87), respectively). There were no significant differences of the EBC pH between the disease groups. When divided into different subgroups, an influence of inhaled steroid treatment was found with steroid-naive recurrent wheezers having significantly lower EBC pH levels compared to healthy controls (7.80 (6.95-8.37), P = 0.018), but not so steroid treated (7.94 (7.24-8.39), P = 0.055). Both, recurrent wheezers with or without a positive allergy test had significantly lower EBC pH compared to healthy controls (7.91 (6.95-8.37), P = 0.007 and 7.82 (7.32-8.39), P = 0.005, respectively). This study indicates that EBC can be collected with a modified commercially available EBC sampler in infants and young children. Further studies need to be performed to evaluate the relevance and meaning of pH differences of EBC in this age group.     

阻塞性睡眠呼吸暂停低通气综合征呼出气冷凝液8-异前列烷的昼夜变化及其意义

目的 探讨阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea-hypopnea syndrome,OSAHS)患者呼出气冷凝液(exhaled breath condensate,EBC)8-异前列烷(8-isoprostane,8-isoPG)的昼夜变化及其意义.方法 采用德国JAEGER公司的呼出气收集器.收集40例OSAHS患者和30名正常对照者睡眠监测前后的EBC,同时采集睡眠监测后的血清,采用酶联免疫技术测定EBC及血清中8-isoPG的含量,并与睡眠监测指标进行相关性分析.结果 OSAHS组EBC中8-isoPG睡眠监测前为(13.08±1.42)ng/L、睡眠临测后为(14.93±1.39)ng/L(P<0.01).正常对照组EBC中8-isoPG睡眠监测前为(11.06±0.72)ng/L、睡眠监测后为(10.97±0.70)ng/L(P>0.05).OSAHS组睡眠监测后EBC及血清中8-isoPG比正常对照组升高,P<0.01.OSAHS患者睡眠监测后EBC 8-isoPG与血清8-isoPG呈正相关(r=0.685,P<0.01),与AHI呈正相关(r=0.650,P<0.05),与睡眠中最低血氧饱和度、基础血氧饱和度和平均血氧饱和度呈负相关(r=-0.406,-0.439,-0.454,P值均<0.05).结论 OSAHS患者存在夜间氧化应激反应增强,OSAHS患者早晨EBC中8-isoPG可以作为评价患者氧化应激状态和估计病情严重程度的较好指标.     

Reduced exhaled breath condensate pH in asthmatic smokers using inhaled corticosteroids

Background and objectives:   Exhaled breath condensate (EBC) pH has been proposed as a biomarker of airway inflammation and oxidative stress in asthma. Cigarette smoking reduces EBC pH in mild asthma. The effects of smoking on EBC pH in more symptomatic asthmatic patients using inhaled corticosteroids (ICS) are unknown. We aimed to compare EBC pH in asthmatic smokers (AS) and non-smokers (ANS) with moderate to severe disease, who were taking ICS. We also investigated the relationship between EBC pH and biomarkers of airway inflammation and oxidative stress.
Methods:   AS ( n  = 18) and ANS ( n  = 17), who were using ICS, were recruited and EBC pH, sputum inflammatory cell counts and sputum supernatant 8-isoprostane concentrations were measured. Full lung function testing was performed.
Results:   EBC pH was significantly lower in AS than in ANS (6.91 vs 7.41). In AS there was a significant inverse correlation between EBC pH and 8-isoprostane levels ( r  = −0.54, P  = 0.03). There was no correlation between EBC pH and sputum neutrophil counts.
Conclusions:   EBC pH appears to be a biomarker of the level of oxidative stress in smokers with moderate to severe asthma. EBC pH may have applications for the longitudinal monitoring of the effects of smoking on the airways of asthmatic patients.     

Efecto de la presión positiva continua en las vías aéreas y de la cirugía de las vías aéreas superiores sobre los biomarcadores en condensado de aire exhalado y en suero en pacientes con apnea del sueño

Introduction

Studies on inflammation biomarkers in serum and in exhaled breath condensate (EBC) in obstructive sleep apnea (OSA) have shown conflicting results. The objective of this study is to assess EBC and serum biomarkers in OSA patients at baseline and after continuous positive airway pressure (CPAP) or upper airway surgery (UAS).

Patients and methods

Nine OSA patients referred for UAS were matched for anthropometric characteristics and apnea-hypopnea index with 20 patients receiving CPAP. pH, nitrite (NO₂⁻), nitrate and interleukin 6 in EBC and NO₂⁻, nitrate, leukotriene B₄ and interleukin 6 in serum were determined. EBC and serum samples were collected at baseline and 3 months after CPAP or UAS.

Results

Patients’ mean body mass index was 30 (range 24.9-40) kg/m². EBC biomarker levels at baseline were within normal range and did not differ significantly after CPAP or UAS. No significant changes were observed in the serum concentration of the biomarkers determined after CPAP but the serum concentration of NO₂⁻ increased significantly at 3 months after UAS (P = .0078).

Conclusion

In mildly obese OSA patients, EBC biomarkers of inflammation or oxidative stress were normal at baseline and remained unchanged 3 months after UAS or CPAP. Although UAS was not effective in terms of reducing OSA severity, it was associated with an increase in serum NO₂⁻.     

Acute effects of smoking and food consumption on breath condensate pH in healthy adults

Acute effects of food and cigarette consumption on exhaled breath condensate (EBC) acidity are insufficiently explored. The study aimed to evaluate potential changes in EBC pH within 2 hours following cigarette or food consumption. In 15 healthy smokers, samples were obtained after 10 hours of abstinence from smoking and then 15, 30, 60, and 120 minutes after smoking 1 cigarette. In 19 healthy nonsmoking adults, EBC samples were obtained in the morning after an overnight fast, and then 30, 60, and 120 minutes following standardized breakfast. Smoking of 1 cigarette after overnight tobacco abstinence induced significant increase in EBC pH during the 2-hour observation period, for approximately 0.60 logarithmic units (repeated-measures analysis of variance [ANOVA], P < .0001). The average presmoking pH value in smokers (7.00 ± 0.50) was significantly lower than average value in nonsmokers (7.62 ± 0.31; P = .0001). No effect of food consumption was found. These results show that cigarette smoking acutely increases EBC pH in healthy smokers. Smoking status and abstinence from smoking before EBC sampling seems to be important in studies evaluating EBC pH and should be standardized or at least stated in the methodology. Acute effects of food were not found under described study conditions in healthy adults.     

Exercise increases exhaled breath condensate cysteinyl leukotriene concentration in asthmatic patients

Background. Although the importance of cysteinyl leukotrienes (Cys-LTs) in exercise-induced bronchoconstriction (EIB) is supported by various sources of evidence, how the concentration of these mediators change during the development of EIB has not been investigated. Objectives. Our goal was to determine the effect of exercise on the concentration of airway Cys-LT in asthmatic patients by measuring Cys-LT in exhaled breath condensate (EBC). Methods. Seventeen atopic asthmatic patients with a previous history of EIB and six healthy volunteers were studied. Before and two times within 10 minutes after exercise challenge, FEV₁ was measured and EBC was collected for Cys-LT measurement. Exhaled nitric oxide level, a marker of airway inflammation, was also determined at baseline. Results. Baseline Cys-LT level was higher in the asthmatic group versus healthy subjects (168 pg/mL /112–223/ vs. 77 pg/mL /36–119/, p = .03). EBC Cys-LT concentration increased in all asthmatic patients post-exercise (n = 17, p = .03), with the increase significantly greater in patients developing exercise-induced bronchospasm (n = 7, p = .03), whereas no change was observed in healthy controls (p = .59). The exercise-induced fall in FEV₁ in asthmatics was related to the increase in EBC Cys-LT concentration (r = ?0.40, p = .03). Conclusions. Our study shows that Cys-LT concentration of EBC is elevated minutes after physical exercise in asthmatic patients and strongly supports the concept that the release of this mediator is involved in the development of EIB.