BackgroundSystemic inflammation associated with sepsis can induce neuronal hyperexcitability, leading to enhanced seizure predisposition and occurrence. Brain microglia are rapidly activated in response to systemic inflammation and, in this activated state, release multiple cytokines and signaling factors that amplify the inflammatory response and increase neuronal excitability. NADPH oxidase (NOX) enzymes promote microglial activation through the generation of reactive oxygen species (ROS), such as superoxide anion. We hypothesized that NOX isoforms, particularly NOX2, are potential targets for prevention of sepsis-associated seizures.MethodsTo reduce NADPH oxidase 2-derived ROS production, mice with deficits of NOX regulatory subunit/NOX2 organizer p47phox (p47phox−/−) or NOX2 major subunit gp91phox (gp91phox−/−) were used or the NOX2-selective inhibitor diphenyleneiodonium (DPI) was used to treat wild-type (WT) mice. Systemic inflammation was induced by intraperitoneal injection of lipopolysaccharide (LPS). Seizure susceptibility was compared among mouse groups in response to intraperitoneal injection of pentylenetetrazole (PTZ). Brain tissues were assayed for proinflammatory gene and protein expression, and immunofluorescence staining was used to estimate the proportion of activated microglia.ResultsIncreased susceptibility to PTZ-induced seizures following sepsis was significantly attenuated in gp91phox−/− and p47phox−/− mice compared with WT mice. Both gp91phox−/− and p47phox−/− mice exhibited reduced microglia activation and lower brain induction of multiple proconvulsive cytokines, including TNFα, IL-1β, IL-6, and CCL2, compared with WT mice. Administration of DPI following LPS injection significantly attenuated the increased susceptibility to PTZ-induced seizures and reduced both microglia activation and brain proconvulsive cytokine concentrations compared with vehicle-treated controls. DPI also inhibited the upregulation of gp91phox transcripts following LPS injection.ConclusionsOur results indicate that NADPH oxidases contribute to the development of increased seizure susceptibility in mice after sepsis. Pharmacologic inhibition of NOX may be a promising therapeutic approach to reducing sepsis-associated neuroinflammation, neuronal hyperexcitability, and seizures.Electronic supplementary materialThe online version of this article (10.1186/s12974-018-1186-5) contains supplementary material, which is available to authorized users.

BackgroundSalmonella meningitis remains a threat to children below two years of age in both developing and developed countries. However, information on such infections has not been well characterized. We analyzed data related to twelve years of experience in order to clarify the comprehensive features of Salmonella meningitis in our patients, including admission characteristics, acute complications, and long-term outcome.MethodsThe records of patients with spontaneous Salmonella meningitis from 1982 to 1994 were retrospectively reviewed. The long-term outcome was prospectively determined for survivors at school age by the developmental milestones reported by their parents and detailed neurological evaluation along with intelligence, hearing, visual, speech and language assessments.ResultsOf the twenty-four patients, seizures were noted in fifteen (63%) before admission and thirteen (54%) during hospitalization. Acute complications mainly included hydrocephalus (50%), subdural collection (42%), cerebral infarction (33%), ventriculitis (25%), empyema (13%), intracranial abscess (8%), and cranial nerve palsy (8%). Three patients (13%) died during the acute phase of Salmonella meningitis. The twenty-one survivors, on whom we followed up at school age, have sequelae consisting of language disorder (52%), motor disability (48%), intelligence quotient < 80 (43%), epilepsy (33%), sensorineural hearing loss (17%), visual deficits (10%), abducens nerve palsy (5%), microcephaly (5%), and hydrocephalus (5%). Overall, good outcome was noted in six (28.6%) of twenty-one survivors, mild sequelae in three (14.2%), moderate in six (28.6%), and severe in six (28.6%).ConclusionSalmonella meningitis in neonates and infants had a wide spectrum of morbidity and acute complications, leading to a complicated hospital course and subsequently a high prevalence of permanent adverse outcome. Thus, early recognition of acute complications of Salmonella meningitis and a follow-up plan for early developmental assessment of survivors are vital.

Blue, green, and yellow phosphors are obtained in the Sr1−xY0.98+xCe0.02Si4N7−xCx system (x=0→1). Decreases in thermal quenching barrier height with x result from a dominant neighboring‐cation effect, through which the replacement of Sr2+ by Y3+ reduces the covalency of CeN bonding. Green emission is observed from a cation‐segregated nanostructure of SrYSi4N7 and Y2Si4N6C domains in x=0.2–0.6 samples.

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