Development of Artificial Cerebrospinal Fluid: Basic Experiments, and Phase II and III Clinical Trials

Abstract

Objectives: The first artificial cerebrospinal fluids (ACSFs), Elliot’s solutions A and B, were first reported in 1949. In 1974, we developed an ACSF, ACSF trial product No. 1, and have safely used and developed this ACSF since then (No.1 to No.19). In parallel with this, after performing basic experiments and clinical trials, we obtained marketing approval for a commercially available ACSF (ARTCEREB) from the Japanese Ministry of Health, Labor, and Welfare in 2008. We now present the results of those basic experiments and clinical studies, including the phase II and III trials on ARTCEREB, with special reference to its safety and efficacy. Methods: The composition and properties of ARTCEREB are as the same as human CSF, excluding the Clconcentration. Experiments with rats: the significance of bicarbonate in ACSF, and the influence and cytotoxicity of ARTCEREB, lactated Ringer’s solution, and normal saline were assessed in cultured brain cells derived from rat fetuses by examining mitochondrial activity and morphological changes. In rats with brain injury, we examined the influence of these three irrigation and perfusion fluids on edema, vascular permeability, and mitochondrial activity. Clinical trials: we performed the phase II and III clinical trials on 157 patients in 17 institutions from 2002 through 2005. Results: Experiments with rats: the morphological changes observed in the ARTCEREB-treated group were less than in the other two groups. Mitochondrial activity was higher in the ARTCEREB group than observed for the other two solutions. Mitochondrial activity in the ARTCEREB, lactated Ringer’s solution, and normal saline groups was approximately10%, 50%, and 70%, respectively, lower than observed in intact cultured brain cells. There was a significant reduction of edema and vascular permeability at the injured site in the ARTCEREB group compared to the other two groups. Mitochondrial activity was significantly higher in the ARTCEREB group than in the other two groups, indicating the lower cytotoxicity of ARTCEREB. Clinical trials: the only adverse effects associated with the use of ARTCEREB were a slightly increased temperature in two patients and decreased alkaline phosphatase activity in two patients, indicating the safety and efficacy of ARTCEREB. Conclusions: In the present study, basic experiments on cultured brain cells derived from rat fetuses and in the injured rat brain, combined with phase II and III clinical trials demonstrated the safety and efficacy of ARTCEREB