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Objective. Although spirometry is the most common method for evaluating the airway obstruction stage in asthma patients, it is difficult to perform in some patients. The aim of this study was to evaluate whether impulse oscillometry, an easy-to-perform technique, can detect asthmatic airway obstruction stage. Methods. A total of 80 subjects, including healthy volunteers and patients with asthma, were enrolled in this study. The asthma patients were classified into three groups according to American Thoracic Society (ATS)/European Respiratory Society (ERS)-2005: the mild group (forced expiratory volume in 1 second (FEV1) ≥ 70% predicted (Pred), n = 20), the moderate group (50% Pred ≤ FEV1 <70% Pred, n = 20), and the severe group (FEV1 < 50% Pred, n = 20). Spirometry and impulse oscillometry (IOS) parameters were obtained from every subject. Correlation analysis was used to compare spirometry measurements and IOS parameters. One-way analysis of variance (ANOVA) was performed to compare IOS parameters among different groups. The potential of using all individual IOS parameters to detect the different stages of asthmatic airway obstruction was evaluated by the receiver operating characteristic (ROC) curve analysis. Results. The correlation analysis showed that IOS parameters, such as respiratory resistance at 5 Hz ( R5), respiratory resistance at 10 Hz ( R10), respiratory resistance at 20 Hz ( R20), difference in resistance between 5 Hz and 20 Hz ( R5-20), impedance at 5 Hz ( Z5), resonant frequency (Fres), and area of reactance (AX) were negatively correlated with FEV1 and peak expiratory flow (PEF), while reactance at 5 Hz ( X5) was positively correlated with FEV1 and PEF. The increase in R5, R10, R20, Z5, R5-20, Fres, (− X5), and AX parameters corresponded significantly with an increase in the airway obstruction stage, as determined by one-way ANOVA . ROC curve analysis revealed that all the IOS parameters studied, except for Fres, were capable of classifying asthmatic airway obstruction. R5, R5-20, and Z5 were the most accurate parameters. Conclusion. IOS provides an accurate, reliable, and patient-friendly technique for classifying asthmatic airway obstruction. [ABSTRACT FROM AUTHOR]

An in vivo study on enhancing epirubicin hydrochloride (EPI) inhibition on tumor growth by ultrasound (US) was reported. Five-week-old male nude mice were used and HL-60 cells were s.c. (subcutaneous injection) inoculated in axilla of these mice. Six groups were designed and five consecutive treatments were applied to investigate the inhibition on tumor growth and body weight growth. US applied locally to the tumor resulted in a substantially increased drug uptake in tumor cells. The inhibition on tumor growth depended on the position of drug injection and phospholipid-based microbubble (PMB) application. Tumor growth rate under group 1 (PMB+US) was similar to that of blank control. The order of the inhibition on tumor volume growth was: group 4 (s.c. EPI+PMB+US) > group 5 intraperitoneal (i.p. EPI+PMB+US) > group 2 (i.p. EPI) > group 3 (s.c. EPI+US) > group 1 (PMB+US). Similar conclusion was obtained from experimental measurements of tumor weight change. The order of animal survival status for EPI administration groups was: group 4 > group 5 > group 2 > group 3. Chemotherapeutic drug inhibition on tumor growth could be enhanced by local US combined with PMB, which might provide a potential application for US-mediated chemotherapy. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the factors for enhancing the susceptibility of cancer cells to chemotherapeutic drug by ultrasound microbubbles. Ultrasound (US) combined with phospholipid-based microbubbles (MB) was used to enhance the susceptibility of colon cancer cell line SWD-620 to anticancer drugs Topotecan hydrochloride (TOP). Experiments were designed to investigate the influence of main factors on cell viability and cell inhibition, such as US intensity, MB concentration, drug combination with MB, asynchronous action between US triggered cavitation and drug entering cell, MB particle size. US exposure for 10 sec with US probe power at 0.6 W/cm2 had satisfied cell viability. Treated with US combined with 15% MB, cell viability maintained more than 85% and cell inhibition 86.16%. Under optimal US combined with MB, TOP showed much higher cell inhibition than that of only TOP group. Cell inhibition under short delayed time (<2 h) for TOP addition did not show obvious difference. In terms of MB particle size, the order of cell inhibition was: Mixture > Micron bubble part > Nanometer bubble part. US combined with MB can enhance the susceptibility of cancer cells to chemotherapeutic drug, which may provide a potential method for US-mediated tumor chemotherapy. [ABSTRACT FROM AUTHOR]