Development of a standardized and validated flow cytometry approach for monitoring of innate myeloid immune cells in human blood

Innate myeloid cell (IMC) populations form an essential part of innate immunity. Flow cytometric (FCM) monitoring of IMCs in peripheral blood (PB) has great clinical potential for disease monitoring due to their role in maintenance of tissue homeostasis and ability to sense micro-environmental changes, such as inflammatory processes and tissue damage. However, the lack of standardized and validated approaches has hampered broad clinical implementation. For accurate identification and separation of IMC populations, 62 antibodies against 44 different proteins were evaluated. In multiple rounds of EuroFlow-based design-testing-evaluation-redesign, finally 16 antibodies were selected for their non-redundancy and separation power. Accordingly, two antibody combinations were designed for fast, sensitive, and reproducible FCM monitoring of IMC populations in PB in clinical settings (11-color; 13 antibodies) and translational research (14-color; 16 antibodies). Performance of pre-analytical and analytical variables among different instruments, together with optimized post-analytical data analysis and reference values were assessed. Overall, 265 blood samples were used for design and validation of the antibody combinations and in vitro functional assays, as well as for assessing the impact of sample preparation procedures and conditions. The two (11- and 14-color) antibody combinations allowed for robust and sensitive detection of 19 and 23 IMC populations, respectively. Highly reproducible identification and enumeration of IMC populations was achieved, independently of anticoagulant, type of FCM instrument and center, particularly when database/software-guided automated (vs. manual "expert-based") gating was used. Whereas no significant changes were observed in identification of IMC populations for up to 24h delayed sample processing, a significant impact was observed in their absolute counts after >12h delay. Therefore, accurate identification and quantitation of IMC populations requires sample processing on the same day. Significantly different counts were observed in PB for multiple IMC populations according to age and sex. Consequently, PB samples from 116 healthy donors (8-69 years) were used for collecting age and sex related reference values for all IMC populations. In summary, the two antibody combinations and FCM approach allow for rapid, standardized, automated and reproducible identification of 19 and 23 IMC populations in PB, suited for monitoring of innate immune responses in clinical and translational research settings

High-speed liquid chromatography of sugar acids on anion-exchange resins

SUMMARY Mixtures of aldonic and aldaric acids are difficult to analyse. Aldonic acids can be separated in a satisfactory way on anion-exchange resins with a solution of sodium chloride as eluent. Under these circumstances, however, aldaric acids show unacceptably long elution times and peak broadening. The ability of aldaric acids to form non-adsorbable complexes with magnesium ions lowers their elution times, particularly of the low-molecular-weight acids, by up to 25 fold. This effect can be controlled by adjusting the magnesium ion concentration in the eluent. It is thus possible to achieve rapid, accurate analysis of mixtures of aldonic and aldaric acids by a proper choice of the magnesium and chloride ion concentrations in the eluent

β-blokkers en elektroconvulsietherapie: Een review

BACKGROUND: When patients with cardiovascular disorders undergo electroconvulsive therapy (ECT) they sometimes have to be treated for tachycardia and high blood pressure. AIM: To describe the effects of β-blockers on seizure duration and cardiovascular variables in patients undergoing ECT. METHOD: Search for studies in Medline, with the keywords 'beta-adrenergic blocking agents' and 'electroconvulsive therapy'. Only articles based on randomised placebo-controlled investigations were included. RESULTS: The search strategy produced 21 articles. These were assessed by all authors. Esmolol was the drug administered in most of the trials. Since seizure duration can influence the therapeutic effect of ECT it is advisable to use bilateral electrode placement in patients with cardiovascular risk factors and to administer esmolol prior to seizure induction. CONCLUSION: The beta-blocker of choice for use during ECT seems to be esmolol; it can shorten seizure duration, although the effect is probably dose-dependent. Esmolol is also the drug of choice in ECT sessions for patients without cardiovascular risk factors but who develop prolonged hypertension or tachycardia. A possible alternative is labetalol, but its longer half-life is a disadvantage, particularly if it is administered in a high dose. So far, experience with landiolol is limited, but its short half-life, greater cardioselectivity and higher potency mean that it could be a promising alternative