Robust and rapid partitioning in thermoplastic

Partitioning is the core technology supporting digital assays. It divides a sample into thousands of individual reactors prior to amplification and absolute quantification of target molecules. Thermoplastics are attractive materials for large scale manufacturing, however they have been seldomly used for fabricating partitioning arrays. Patitioning in thermoplastic devices has proven difficult due to the challenge of efficiently displacing the air trapped in the nanoliter structures during priming of thousands of chambers. Here, we report the design of an array of chambers made of thermoplastics where the progression of the liquid-air interface is controlled by capillary effects. Our device performs robust partitioning over a wide range of pressures and can be actuated at low pressure by a simple micropipette. Our thermoplastic device lays the foundation to cost-effective and instrument-free partitioning platforms, which could be deployed in low-resource settings.

Serum potassium levels, CPK-MB and ECG in children suffering asthma treated with beclomethasone or beclomethasone-salmeterol

Asthma morbidity and mortality has increased. One of the possible causes is the excessive use of beta agonists. The aim of this study is to compare the effects of six week treatment with beclomethasone alone (Ibec) or the combination of beclomethasone-salmeterol (Ibe + Isal) on serum potassium (K), CPK-MB and ECG in children suffering asthma. It was a prospective, randomised, open cross-over trial. Patients received either Ib2 (2 puff/12 hr, 100 micrograms per puff) or Ibe + Isal (B 2 puff/12 hr, 100 micrograms per puff and S 2 puff/12 hr, 25 micrograms per puff) with dose meter inhaler by 6 weeks, with a four-week wash-out period between the treatments. K, CPK-MB and ECG were assessed at baseline, and after each treatment period. There were 9 girls and 20 boys, aged 11 +/- 2.18 (mean +/- SD) years, baseline K was 4.57 +/- 0.43 mEq/l, after B K 4.38 +/- 0.39 IU and after BS K 4.38 +/- 0.40. The CPK-MB level were baseline 14.75 +/- 4.5, after B 20.10 +/- 6.9 and after BS 21 +/- 8.05 (p < 0.05). Baseline QTc was 0.416 +/- 0.02 msec, after B 0.425 +/- 0.027, and after BS 0.415 +/- 0.029. We conclude that the treatment of children with asthma with 400 micrograms per day of Ibec or concomitantly with 100 micrograms of Isal for 6 weeks does not alter the serum K+ or the QTc. However, the CPK-MB has a significant increment with both treatments but without clinical and/or ECG changes. We can't affirm that Ibec or Ibec plus Isal have a cardiotoxic side-effect by the only presence of high levels of CPK-MB. We agree that it is necessary a close follow up of these apparently asymptomatic patients not induce important cardiovascular changes although CPK-MB was increased.