Glow flow ionization mass spectrometry of small molecules. A comparison of a glow flow ionization source ('GlowFlow') with electrospray ionization and atmospheric pressure chemical ionization.

RATIONALE: Ionization by atmospheric pressure gas discharge has been employed for a long time in mass spectrometry. Inductively coupled plasma mass spectrometry is an exemplar, and widely used for elemental analysis. The technique has less uptake in organic mass spectrometry. We describe a simple source design that can be readily implemented in most atmospheric pressure ionization (API) systems and compare its performance with that of electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). METHODS: An in-house designed helium gas discharge source (referred to as 'GlowFlow') was used on a Xevo G2-S time-of-flight mass spectrometer. The GlowFlow source was transferred to a compatible Xevo TQ-S triple-quadrupole mass spectrometer using an ultrahigh-performance liquid chromatograph inlet. Its performance was compared to that of Waters ESI and APCI sources. RESULTS: Preliminary results of GlowFlow on the Swansea instrument are presented to establish context and include analysis of low-molecular-mass polymers, benzoic acid and cinnamic acid. Comparison of performance on the Xevo TQ-S triple-quadrupole mass spectrometer involved three test mixtures. The method limits of detection (six-mix) for positive-ion GlowFlow source were between 0.03 and 10.00 pg with good linear response over two to four orders of magnitude and values of R2 > 0.98. The GlowFlow ionization source provided a signal intensity that was an order of magnitude greater than that of ESI for an atmospheric pressure gas chromatography standard mix and ionized several compounds that ESI could not. CONCLUSIONS: The current GlowFlow design is relatively simple to retrofit to most API systems due to its small size. The sensitivity of the GlowFlow design is typically an order of magnitude less than that of ESI in positive-ion mode, but similar in sensitivity in negative-ion mode and comparable to that of APCI.

Rezidivierende fulminante Myokarditis mit wiederholtem Einsatz der ECMO bei einem Kind.

Recurrent myocarditis is rare with only few reports having been published for paediatric cases. Repeated use of extracorporeal membrane oxygenation is also uncommon. In this paper we will present a very rare case of a 7-year old girl with recurrent fulminant myocarditis with heart failure requiring cardiopulmonary resuscitation and mechanical circulatory support with extracorporeal membrane oxygenation. Both episodes were precipitated by a viral upper respiratory tract infection, and in both cases the cardiac function eventually completely recovered. The second episode of fulminant myocarditis was particularly complex with markedly elevated markers of myocardiocytolysis, multiorgan dysfunction and the need for prolonged mechanical circulatory support. Nevertheless, the patient made a remarkable recovery. A comprehensive diagnostic workup pointed towards an aberrant immune response as the likely cause of the girl's susceptibility for fulminant myocarditis.

Aortic valve regurgitation following percutaneous closure of patent ductus arteriosus.

OBJECTIVES: To determine the incidence and outcome of aortic valve regurgitation (AR) following the percutaneous closure of patent ductus arteriosus (PDA). BACKGROUND: Aortic valve regurgitation is an overlooked consequence of percutaneous PDA closure. METHODS: Between December 2000 and May 2009, 51 children underwent percutaneous closure of PDA using Amplatzer Duct Occluders. Their median age at the time of the procedure was 2.6 years (range: 0.6-18.0 years), and median weight was 14.0 kg (range: 7.6-75.0 kg). Follow-up echocardiograms were performed a day after the procedure and at 1, 3, 12 months, and yearly thereafter. RESULTS: A day after the procedure, AR was detected for the first time in 13 of 48 patients (27.0%). A group of patients with newly developed AR was significantly different from a group of patients with competent aortic valves with respect to their age, weight, and minimal PDA diameter indexed to the body weight. The follow-up period ranged from 0.2 to 8.5 years (median 3.3 years) and at the latest follow-up evaluation, AR persisted in a single patient (2.0%) 6 years after the procedure. CONCLUSIONS: The aortic valve regurgitation following percutaneous PDA closure is trivial to mild and transient. It develops in approximately a quarter of children after percutaneous closure of PDA with a minimal diameter≥1.5 mm and is more likely to develop in infants and small children having significant left-to-right shunts.