Liposomal Artificial Red Blood Cell-Based Carbon Monoxide Donor Is a Potent Renoprotectant against Cisplatin-Induced Acute Kidney Injury

Cisplatin (CDDP) is an essential anti-tumor agent for chemotherapeutic regimens against various types of cancer. However, the progression of nephrotoxicity, which is the main adverse effect of CDDP, leads to discontinuation of CDDP chemotherapy. Therefore, development of a renoprotectant against CDDP-induced nephrotoxicity is crucial. Here, the potential of a carbon monoxide (CO)-loaded hemoglobin-vesicle (CO-HbV) as a renoprotectant for CDDP-induced nephrotoxicity was evaluated for its renoprotective effects against CDDP-induced nephrotoxicity, inhibitory effects on the anti-tumor activity of CDDP, and anti-tumor activity. In healthy mice, after pretreatment with either saline, HbV, or CO-HbV prior to CDDP administration, only the CO-HbV pretreatment group ameliorated the progression of CDDP-induced nephrotoxicity by suppressing apoptosis via caspase-3. In experiments using B16-F10 melanoma cells, the half-maximal inhibitory concentration of CDDP decreased with co-incubation with CO-HbV, owing to the anti-tumor activity of CO. CO-HbV pretreatment had no impact on the anti-tumor activity of CDDP in B16-F10 melanoma cell-bearing mice, which was consistent with the results of the cell experiment. Furthermore, CO-HbV pretreatment improved body growth and survival rates. In conclusion, CO-HbV pretreatment is a potent renoprotectant for CDDP-induced nephrotoxicity, allowing treatment with CDDP to be conducted without failure of cancer treatment.

The optimal trough-guided monitoring of vancomycin in children: Systematic review and meta-analyses

We carried out a systematic review and meta-analysis exploring the relationship between vancomycin (VCM) trough concentrations and its effectiveness and nephrotoxicity in pediatric patients. We conducted our analysis using MEDLINE, Web of Sciences, and Cochrane Register of Controlled Trials as electronic databases (June 29, 2019). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. We identified 16 studies that were eligible for the meta-analysis. A total of 351 and 3,266 patients were included in the analysis for effectiveness and nephrotoxicity, respectively. Pediatric MRSA infection patients with VCM trough concentrations ≥ 10 μg/mL had significantly lower treatment failure rates (OR 0.54, 95% CI 0.30-0.96). The incidence of nephrotoxicity was significantly higher in trough concentrations ≥ 15 μg/mL than when they were < 15 μg/mL (OR 3.02, 95% CI 2.08-4.38). We identified the optimal VCM trough concentrations associated with effectiveness and nephrotoxicity in pediatric patients with MRSA infection. Further prospective studies are needed to find optimal dosing and monitoring strategy on VCM in pediatric population.

Cloning of a functional splice variant of L-type calcium channel beta 2 subunit from rat heart

L-type Ca(2+) channels are heteromultimeric and finely tuned by auxiliary subunits in different tissues and regions. Among auxiliary subunits, beta subunit has been shown to play important roles in many functional aspects of Ca(2+) channel. Rat heart was reported to specifically express beta(2a) subunit. However, the slow inactivation rates of Ca(2+) currents recorded from recombinant Ca(2+) channels with the beta(2a) subunit, and the reported inability to detect beta(2a) subunit in rabbit heart by reverse transcription-PCR analysis raise the possibility of the existence of other beta subunits. We cloned a splice variant of beta(2) subunit from rat heart, using rapid amplification of cDNA 5' ends. The splice variant is highly similar to human beta(2c) subunit that was cloned from human ventricle. Northern blot analysis detected the rat beta(2c) subunit abundantly in rat heart and brain. The deduced amino acid sequence of the beta(2c) subunit was different from that of the beta(2a) subunit only in the N-terminal region. When the beta(2c) subunit was expressed along with alpha(1c) and alpha(2)delta subunits in baby hamster kidney cells, the inactivation rates were comparable with those from native cardiac myocytes, although those with the beta(2a) subunit were slow. Taken together, these observations suggest that the beta(2c) subunit is a functional beta(2) subunit expressed in heart and that the short N-terminal region plays a major role in modifying inactivation kinetics.