Prescribed drugs and polypharmacy in healthcare service users in South Korea: an analysis based on National Health Insurance Claims data.

OBJECTIVE: This study was conducted to analyze and compare the exposure to individually prescribed drugs and the prevalence of polypharmacy according to age group and concomitant disease in South Korea. METHODS: The use of prescribed drugs was evaluated according to average numbers of prescription drugs used daily during a year or month, using the Korean Health Insurance Claims Database, which is representative of over 90% of citizens, in 2010 and 2011. The use of prescribed drugs was also analyzed according to concomitant diseases and age. Polypharmacy was defined as the use of 5 or more drugs daily during a specific observation period, and proportions of polypharmacy users were calculated according to comorbidity and age group. RESULTS: The annual average numbers of daily used prescription drugs in 2010 and 2011 were 0.3 (SD = 0.5), 0.4 (SD = 0.7), 1.2 (SD = 1.5), and 2.3 (SD = 2.0) for people aged < 20 years, 20-49 years, 50-64 years, and ≥ 65 years, respectively. Proportions of individuals demonstrating polypharmacy increased with age and were 9.5% and 44.1% for elderly individuals in the year- and month-based analyses, respectively. The annual average number of daily medications used increased by ~2 drugs in the concomitant disease group, and the higher mortality group used a higher number of prescribed drugs than the lower mortality group. CONCLUSIONS: The results highlight the elevated burden of multi-medication in elderly patients, and the study found that prescribed drug use increased with age and the number of concomitant diseases.

Adsorptive loss of secreted recombinant proteins in transgenic rice cell suspension cultures.

Adsorptive loss of human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) in transgenic rice cell suspension cultures was investigated using glass flasks, plastic flasks, disposable vessels, and stainless steel vessels. When hCTLA4Ig was added to the glass flasks containing sterile AA medium, a rapid decrease in the concentration of hCTLA4Ig, independent on pH, was observed resulting in more than 90% of the protein loss within 1 h due to the surface adsorption. When the same experiments were performed on four different types of culture equipments mentioned above, the lowest adsorption level was observed in the plastic flasks and the highest level was observed in the glass flasks. The use of the plastic flasks retarded the adsorptive loss of hCTLA4Ig at the early stage of the protein production. There was a significant increase in the production of hCTLA4Ig when the flasks were coated with bovine serum albumin. However, the spike test of purified hCTLA4Ig at two different concentrations of 15 and 100 mg L(-1) in 500-mL spinner flasks confirmed that the amount of hCTLA4Ig adsorbed was dependent on the surface area of the flasks but not on the concentrations. In conclusion, although the protein adsorption affected the total amount of the protein yielded to some extent, it could be regarded as a minor factor in transgenic plant cell cultures with higher titer.

Effects of silkworm hemolymph on cell viability and hCTLA4Ig production in transgenic rice cell suspension cultures.

Silkworm hemolymph (SH), prepared from fifth-instar larvae of Bombyx mori and heat-treated at 60 degrees C for 30 min, was used to improve cell viability and the production of human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) in transgenic Oryza sativa L. cell suspension cultures. Even though SH could not elevate cell viability at the concentrations up to 3% (v/v), addition of 0.3% (v/v) SH to a culture medium enhanced the production of hCTLA4Ig by 36.8% over an SH-free medium. Moreover, the production period of hCTLA4Ig could be shortened in a 0.3% (v/v) SHadded medium compared with that in an SH-free culture. As a result, addition of 0.3% (v/v) SH improved the productivity of hCTLA4Ig significantly in transgenic rice cell cultures.