[The Beneficial Effects of Switching from Dipeptidyl Peptidase-4 Inhibitors to Dulaglutide on Plasma Glucose and Hemoglobin A1c Levels: A Case Report of Four Patients with Type 2 Diabetes].

　Incretin-based therapy consists of dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists. Whether switching from DPP-4 inhibitors to one of the GLP-1 receptor agonists, dulaglutide, has greater beneficial effects remains unknown. Therefore, this study aimed to investigate the effectiveness of switching from DPP-4 inhibitors to dulaglutide in four patients with type 2 diabetes. All four patients with hyperglycemia who switched from DPP-4 inhibitors to dulaglutide demonstrated noticeable decreased plasma glucose levels on the next day after switching. Two of the patients observed maintained a decreased plasma glucose level over 14 day after switching. Moreover, all patients demonstrated decreased glycosylated hemoglobin A1c levels during the observation period (1-6 months) after switching and lost weight from 6 to 27 day. Minor and manageable hypoglycemia, nausea, and diarrhea were observed as side effects in one case. The current findings suggest that dulaglutide is a suitable treatment alternative in patients with type 2 diabetes who are not currently achieving adequate glycemic control with DPP-4 inhibitors.

Ocular gene delivery systems using ternary complexes of plasmid DNA, polyethylenimine, and anionic polymers.

In this experiment, we developed anionic ternary complexes for effective and safe ocular gene delivery. Ternary complexes were constructed by coating plasmid DNA (pDNA)/polyethylenimine (PEI) complex with anionic polymers such as γ-polyglutamic acid (γ-PGA) and chondroitin sulfate (CS). The cationic pDNA/PEI complex showed high gene expression on the human retinal pigment epithelial cell line, ARPE-19 cells. The pDNA/PEI complexes, however, also showed high cytotoxicity on the cells and aggregated strongly in the vitreous body. On the other hand, the anionic ternary complexes showed high gene expression on ARPE-19 cells without such cytotoxicity and aggregation. After intravitreous administration of the complexes, the anionic ternary complexes showed high gene expression in the retina. These results strongly indicate that anionic ternary complexes are suitable for effective and safe ocular gene therapy.

Polyoxyethylene hydrogenated castor oil modulates benzalkonium chloride toxicity: comparison of acute corneal barrier dysfunction induced by travoprost Z and travoprost.

PURPOSE: To determine the element that modulates benzalkonium chloride (BAC) toxicity by using a new electrophysiological method to evaluate acute corneal barrier dysfunction induced by travoprost Z with sofZia (Travatan Z(®)), travoprost with 0.015% BAC (Travatan(®)), and its additives. METHODS: Corneal transepithelial electrical resistance (TER) was measured in live white Japanese rabbits by 2 Ag/AgCl electrodes placed in the anterior aqueous chamber and on the cornea. We evaluated corneal TER changes after a 60-s exposure to travoprost Z, travoprost, and 0.015% BAC. Similarly, TER changes were evaluated after corneas were exposed for 60 s to the travoprost additives ethylenediaminetetraacetic acid disodium salt, boric acid, mannitol, trometamol, and polyoxyethylene hydrogenated castor oil 40 (HCO-40) with or without BAC. Corneal damage was examined after exposure to BAC with or without travoprost additives using scanning electron microscopy (SEM) and a cytotoxicity assay. RESULTS: Although no decreases of TER were noted after exposure to travoprost Z with sofZia and travoprost with 0.015% BAC, a significant decrease of corneal TER was observed after 0.015% BAC exposure. With the exception of BAC, no corneal TER decreases were observed for any travoprost additives. After corneal exposure to travoprost additives with BAC, HCO-40 was able to prevent the BAC-induced TER decrease. SEM observations and the cytotoxicity assay confirmed that there was a remarkable improvement of BAC-induced corneal epithelial toxicity after addition of HCO-40 to the BAC. CONCLUSIONS: Travoprost Z with sofZia and travoprost with BAC do not induce acute corneal barrier dysfunction. HCO-40 provides protection against BAC-induced corneal toxicity.

Influence of alkyl chain length of benzalkonium chloride on acute corneal epithelial toxicity.

PURPOSE: To evaluate acute corneal epithelial toxicity induced by benzalkonium chloride (BAC) homologs with different alkyl chain lengths using an in vivo electrophysiological method. METHODS: BAC homologs with C12, C14, and C16 alkyl chain lengths were used at concentrations of 0.0025%, 0.005%, and 0.01%, respectively. Cytotoxicity of BAC homologs on the normal rabbit corneal epithelial cells was examined by using a WST-1 assay. Corneal transepithelial electrical resistance (TER) was measured in living Japanese white rabbits by 2 Ag/AgCl electrodes placed in the anterior aqueous chamber and on the cornea. TER changes were then evaluated after a 60-second exposure to these BAC homologs. Morphological changes in corneal epithelium after exposure to the BAC homologs were examined using scanning electron microscopy. The antimicrobial activity of BAC homologs against Escherichia coli was also assessed. RESULTS: All BAC homologs caused cytotoxicity and corneal barrier dysfunction in a concentration-dependent manner. However, the degree of corneal toxicity differed among the BAC homologs. Based on cytotoxicity and TER measurement, C14-BAC caused the greatest corneal impairment followed in order of severity by mixed BAC/C16-BAC and C12-BAC. Scanning electron microscopy images indicated an intact corneal epithelium after exposure to 0.005% C12-BAC, whereas 0.005% C14-BAC damaged the epithelium. There were no remarkable differences noted in the antimicrobial activity among the BAC homologs. CONCLUSIONS: Acute corneal epithelial toxicity induced by BAC homologs depends on the alkyl chain length. Thus, the use of C12-BAC instead of commercially available BAC is potentially safer for patients undergoing ophthalmological pharmacotherapy.