A cDNA (814 bp) encoding ornithine decarboxylase (ODC) antizyme (Az) was cloned from the Tobacco cutworm, Spodoptera litura. The open reading frame (ORF) showed an internal stop codon (TGA) on bases 223-224-225, encoding 270 amino acids except for the 223-T. A modified ODC Az cDNA (Slit ODC AzM) by point mutation for removal of the 223-T was introduced into a yeast (Saccharomyces cerevisiae) strain expressing a cloned ODC from the Tobacco cutworm. The transformed strain with ODC AzM exhibited a remarkable inhibition on ODC action, showing 56 % lowered cellular proliferation rate and the decreased cellular polyamine levels by 40.1 % (putrescine), 64.1 % (spermidine) and 58.6 % (spermine) at 48 hrs of cultivation in comparison with the original ODC Az cDNA. These results suggest that the modified ODC Az is expressed regardless of the frame-shifting and the expressed functional protein effectively inhibits the ODC activity.

This study was conducted in order to examine the effects of alcohol-free cetylpyridinium chloride drinking water additive and oral gel on clinical parameters related to periodontal disease in beagle dogs. This study was conducted with healthy 15 beagle dogs. Following a professional teeth cleaning procedure, dogs were divided into three groups. Dogs in the control group received nothing, those in the drinking water additive (DWA) group received 800 ml water with 15 ml of alcohol-free cetylpyridinium chloride drinking water additive daily, and those in the Oral gel (OG) group were treated with oral gel containing alcohol-free cetylpyridinium chloride and 0.05% chlorhexidine gluconate daily. Clinical parameters, including plaque index (PI), calculus index (CI), and gingivitis index (GI) were evaluated at two and four weeks. Dogs in the DWA and OG groups had significantly less plaque than dogs in the control group at two and four weeks (P<0.01, P<0.05). And, at four weeks, CI was significantly lower in the OG group compared to the control group (P<0.05). On GI, similar scores were recorded for all groups during the experimental period. No significant difference was observed between the DWA group and the OG group. The effect of alcohol-free cetylpyridinium chloride drinking water additive was similar to the result for alcohol containing cetylpyridinium chloride mouthwash reported in a previous study. The effect in control of periodontal disease was better in the OG group because of additional chlorhexidine gluconate. However, use of drinking water additive will be more convenient for owners; thus, it will be more effective for achievement of long-term results.