Prenatal fat-rich diet exposure alters responses of embryonic neurons to the chemokine, CCL2, in the hypothalamus.

Maternal consumption of a high-fat diet (HFD) during pregnancy is found to stimulate the genesis of hypothalamic orexigenic peptide neurons in the offspring, while HFD intake in adult animals produces a systemic low-grade inflammation which increases neuroimmune factors that may affect neurogenesis and neuronal migration. Building on this evidence and our recent study showing that the inflammatory chemokine, CCL2, stimulates the migration of hypothalamic neurons and expression of orexigenic neuropeptides, we tested here the possibility that prenatal exposure to a HFD in rats affects this chemokine system, both CCL2 and its receptors, CCR2 and CCR4, and alters its actions on hypothalamic neurons, specifically those expressing the neuropeptides, enkephalin (ENK) and galanin (GAL). Using primary dissociated hypothalamic neurons extracted from embryos on embryonic day 19, we found that prenatal HFD exposure compared to chow control actually reduces the expression of CCL2 in these hypothalamic neurons, while increasing CCR2 and CCR4 expression, and also reduces the sensitivity of hypothalamic neurons to CCL2. The HFD abolished the dose-dependent, stimulatory effect of CCL2 on the number of migrated neurons and even shifted its normal stimulatory effect on migrational velocity and distance traveled by control neurons to an inhibition of migration. Further, it abolished the dose-dependent, stimulatory effect of CCL2 on neuronal expression of ENK and GAL. These results demonstrate that prenatal HFD exposure greatly disturbs the functioning of the CCL2 chemokine system in embryonic hypothalamic neurons, reducing its endogenous levels and ability to promote the migration of neurons and their expression of orexigenic peptides.

Reliability of delayed prothrombin time INR determinations in a central laboratory using off-site blood sampling.

A major concern of centralized anticoagulant measurements with off-site sampling is the reliability of international normalized ratio (INR) determinations on blood that may have been taken from the patient hours before the analysis. We compared INR differences in the blood of patients receiving oral anticoagulants after 24 h storage in four conditions: centrifuged at room temperature, centrifuged at 4 degrees C, uncentrifuged at room temperature and uncentrifuged at 4 degrees C. The INR of centrifuged and uncentrifuged blood left at room temperature for 24 h consistently increased by 6% and, after adjustment, there were no misclassifications in the assessment of the adequacy of anticoagulant treatment. Inconsistent changes were noted in tests of refrigerated centrifuged blood. We conclude that storage of blood at room temperature for 24 h results in a consistent prolongation of the prothrombin time, which after correction can reliably be used to adjust the dose of oral anticoagulants.