Ceftriaxone-induced Encephalopathy: A Pharmacokinetic Approach

We report a case of ceftriaxone-induced encephalopathy correlated with high cerebrospinal fluid concentration. Neurotoxicity of cephalosporin is increasingly reported, especially regarding fourth-generation cephalosporins. The factors influencing the corticospinal fluid (CSF) concentration are plasma concentration, liposolubility, ionization, molecular weight, protein binding and efflux. In our patient, high levels of ceftriaxone (27.9 mg/l) were found in the CSF. β-lactam associated neurotoxicity is mainly related to similarities between GABA and β-lactam ring. Because of disparate CSF/plasma ratio and blood-brain barrier efflux among patients, plasmatic drug monitoring probably cannot be used as a surrogate of CSF concentration. This is, as we know, the first case of described ceftriaxone-induced encephalopathy associated with an objective excessive cerebrospinal concentration.

The Role of NLRP1, NLRP3, and AIM2 Inflammasomes in Psoriasis: Review

Inflammasomes are high-molecular-weight protein complexes that may cleave the two main proinflammatory cytokines, pro-interleukin-1β and pro-interleukin-18, into active forms, and contribute to psoriasis. Despite recent advances made in the pathogenesis of psoriasis, mainly studied as an autoimmune condition, activation of immune response triggers of psoriasis is still not completely understood. Recently, focus was placed on the role of inflammasomes in the pathogenesis of psoriasis. Multiple types of inhibitors and activators of various inflammasomes, inflammasome-related genes, and genetic susceptibility loci were recognized in psoriasis. In this systemic review, we collect recent and comprehensive evidence from the inflammasomes, NLRP1, NLRP3, and AIM2, in pathogenesis of psoriasis.

The Low-Molecular Weight Protein Arginine Phosphatase PtpB Affects Nuclease Production, Cell Wall Integrity, and Uptake Rates of Staphylococcus aureus by Polymorphonuclear Leukocytes

The epidemiological success of Staphylococcus aureus as a versatile pathogen in mammals is largely attributed to its virulence factor repertoire and the sophisticated regulatory network controlling this virulon. Here we demonstrate that the low-molecular-weight protein arginine phosphatase PtpB contributes to this regulatory network by affecting the growth phase-dependent transcription of the virulence factor encoding genes/operons aur, nuc, and psmα, and that of the small regulatory RNA RNAIII. Inactivation of ptpB in S. aureus SA564 also significantly decreased the capacity of the mutant to degrade extracellular DNA, to hydrolyze proteins in the extracellular milieu, and to withstand Triton X-100 induced autolysis. SA564 ΔptpB mutant cells were additionally ingested faster by polymorphonuclear leukocytes in a whole blood phagocytosis assay, suggesting that PtpB contributes by several ways positively to the ability of S. aureus to evade host innate immunity.