Comparison Between Peripheral and Central Blood Cultures in Pediatric Oncology Patients With Blood Stream Infections.

BACKGROUND: Current guidelines for fever in children with cancer recommend obtaining blood cultures from all lumens of the central venous catheter (CVC) and to consider a concurrent peripheral blood culture. We assessed the characteristics of blood stream infections (BSI) in oncology children and compared central and peripheral pathogen growth. METHODS: A prospective, computerized surveillance of BSI in children treated at the oncology unit between May 2014 and July 2020. The growth of the same organism within a month was considered a single episode, ≥2 organisms in the same culture were defined as different episodes. Only children with concomitant cultures, drawn at presentation before initiation of antibiotics were included in the comparison between CVC and peripheral cultures. RESULTS: A total of 139 episodes in 81 children (with implanted Port-A-catheters) were considered true BSI. Of the 94/139 (67.6%) cases where a central and peripheral culture were concomitantly obtained, 52/94 (55.3%) had positive central/peripheral cultures that grew the same organism, 31/94 (33.0%) had positive central cultures only, and 11/94 (11.7%) had positive peripheral cultures only. In 3/94 cases, the organisms that grew from the CVC were not identical to those from the peripheral site. Four of 52 (7.7%) of the same positive central/peripheral pathogens had different susceptibility testing results. Higher CVC removal rates were observed when both peripheral and CVC cultures were positive ( P =0.044). CONCLUSIONS: Overall, 11.7% of BSI episodes were identified only by peripheral culture and 7.7% of paired organisms did not share the same susceptibility test results which emphasizes the importance of a peripheral culture in managing fever in oncology children.

The Neuroprotective Role of Origanum syriacum L. and Lavandula dentata L. Essential Oils through Their Effects on AMPA Receptors.

Lavandula dentata L. and Origanum syriacum L. essential oils have numerous health benefits and properties, such as possessing common components with a variant degree of depressive actions in the central nervous system. We investigated the depressive property of these oils on AMPA receptors, which are responsible for most of the fast-excitatory neurotransmission in the CNS and play a critical role in synaptic plasticity. Since excessive activation of AMPARs has been linked to neurotoxicity leading to various pathologies, we hypothesize that these oils have a neuroprotective role by acting directly on the kinetics of AMPARs. Using Gas Chromatography-Mass Spectrometry (GC/MS) and patch-clamp electrophysiology, the essential oils of L. dentata flowers and O. syriacum leaves were characterized and the whole cell currents were measured with and without the administration of the oils onto HEK293 cells. The current study results showed that the biophysical properties of AMPA receptor subunits showed a decrease in desensitization rate of GluA1 and GluA2 homomers, using O. syriacum, while administering L. dentata oil decreased the desensitization rate of GluA1 and GluA2 homomers, as well as GluA1/2 heteromers. As for the deactivation rate, both oils slowed the deactivation kinetics of all AMPA receptor subunits. Intriguingly, between the two oils, the effect of desensitization and deactivation was of a greater significance for L. dentata oil than O. syriacum. Our data suggest that the two oils contain components that are essential to identify, as those active components underlie the oils' neuronal depressive properties reported, and to extract them to synthesize a potent neuroprotective drug to treat neurological diseases potentially.