RESUMO
Blood cell production arises from the activity of hematopoietic stem cells (HSCs), defined by their self-renewal capacity and ability to give rise to all mature blood cell types. The mouse remains one of the most studied species in hematological research, and markers to define and isolate mouse HSCs are well-established. Given the very low frequency of HSCs in the bone marrow, stem cell pre-enrichment by red blood cell lysis and magnetic cell separation is often performed as part of the isolation process to reduce sorting times. Several pre-enrichment strategies are available, differing in their speed, degree of enrichment, final cell yield, and cost. In the current study, we performed a side-by-side comparison and provide a decision tree to help researchers select a pre-enrichment strategy for mouse HSC isolation depending on their downstream application. We then compared different pre-enrichment techniques in combination with metabolomics analysis of HSCs, where speed, yield and temperature during pre-enrichment are crucial factors, and found that the choice of pre-enrichment strategy significantly impacts the number of metabolites detected and levels of individual metabolites in HSCs.
RESUMO
AIMS: To estimate the prevalence of gestational diabetes mellitus (GDM) in a Danish cohort comparing the current Danish versus the WHO2013 diagnostic criteria, and to evaluate adverse pregnancy outcomes among currently untreated women in the gap between the diagnostic thresholds. METHODS: Diagnostic testing was performed by a 75 g oral glucose tolerance test (OGTT) at 24-28 weeks' gestation in a cohort of pregnant women. GDM diagnosis was based on the current Danish criterion (2-h glucose ≥ 9.0 mmol/L, GDMDK) and on the WHO2013 criteria (fasting ≥ 5.1, 1 h ≥ 10.0 or 2 h glucose ≥ 8.5 mmol/L, GDMWHO2013). Currently untreated women fulfilling the WHO2013 but not the Danish diagnostic criteria were defined as New-GDM-women (GDMWHO2013-positive and GDMDK-negative). Adverse outcomes risks were calculated using logistic regression. RESULTS: OGTT was completed by 465 women at a median of 25.7 weeks' gestation. GDMDK prevalence was 2.2% (N = 10) and GDMWHO2013 21.5% (N = 100). New-GDM was present in 19.4% (N = 90), of whom 90.0% had elevated fasting glucose. Pregnancies complicated by New-GDM had higher frequencies of pregnancy-induced hypertension (13.3% vs 4.1%, p = 0.002), large-for-gestational-age infants (22.2% vs 9.9%, p = 0.004), neonatal hypoglycaemia (8.9% vs 1.9%, p = 0.004) and neonatal intensive care unit admission (16.7% vs 5.8%, p = 0.002) compared to pregnancies without GDM. CONCLUSIONS: GDM prevalence increased tenfold when applying WHO2013 criteria in a Danish population, mainly driven by higher fasting glucose levels. Untreated GDM in the gap between the current Danish and the WHO2013 diagnostic criteria resulted in higher risks of adverse pregnancy outcomes.