[Efficacy of Levofloxacin Hydrate in Febrile Neutropenia for Outpatient Chemotherapy].

Management of febrile neutropenia (FN) is important for the safety of patients undergoing outpatient chemotherapy. Oral antimicrobials are usually prescribed as the initial treatment for FN, and outpatients are instructed to begin medication prior to chemotherapy. However, the effectiveness and safety of the use of these oral antibiotics have not yet been established. In this study, we investigated the effectiveness and safety of levofloxacin hydrate (LVFX) for breast cancer patients with FN, and the factors associated with the onset of FN in 134 breast cancer patients who underwent chemotherapy including the anticancer drug anthracycline (total, 513 courses), in an outpatient chemotherapy department. The effectiveness and safety of LVFX were defined respectively as defervescence within 5 days, and the appearance of side effects such as diarrhea and rashes. Fever was observed in 89 (66%) of the 134 patients, and during 164 (32%) of 513 courses. Defervescence was observed with the LVFX medication in 149 (93%) of 160 courses. The primary side effect was the development of rashes, and only 2 (1%) of the 160 courses were discontinued. Onset of stomatitis during chemotherapy was observed as a factor of FN (odds ratio: 1.36, p<0.05). Our results suggest that the use of LVFX according to the patients' discretion might be an effective and safe option for the management of FN during outpatient chemotherapy.

ATP increases the migration of microglia across the brain endothelial cell monolayer.

The cerebral microcapillary endothelium, known as the blood-brain barrier (BBB), acts as a barrier between the blood and the interstitial fluid of the brain. The BBB therefore controls the passage of nutrients into the central nervous system (CNS). Microglia show a specific affinity for migration into the CNS, and this migration appears to occur independently of BBB integrity. To study the migration of microglia across the BBB, we developed an in vitro co-culture system of mouse brain endothelial cells (MBECs) and Ra2 microglia using Transwell inserts. We first investigated the influence of microglia or ATP, a microglial chemotactic factor, on MBEC barrier integrity. The addition of microglia or ATP led to the disruption of the MBEC monolayer and significantly decreased barrier function as measured by trans-endothelial electrical resistance (TEER) and electric cell-substrate impedance sensing (ECIS). Furthermore, ATP promoted the migration of microglia but not macrophages across the MBEC monolayer. An inhibitor of matrix metalloproteinases (MMPs) decreased the transmigration of microglia in our system, indicating that MMPs play a role in microglial chemotaxis. We specifically identify a role for microglia-derived MMP-2. In conclusion, we offer evidence that microglia migration across the brain endothelial cell monolayer is increased in the presence of ATP in a manner that involves MMP secretion.