Survival rates following medical intensive care unit admission from 2003 to 2013: An observational study based on a representative population-based sample cohort of Korean patients.

The decision as to whether patients should be admitted to a medical intensive care unit (ICU), in the absence of information concerning survival rates or prognostic factors in survival, is often challenging. We analyzed survival trends in relation to hospital discharge and examined patient and hospital characteristics associated with survival following ICU care, using a sample of nationwide claims data in Korea from 2002 through 2013. The Korean government implements a compulsory social insurance program that covers the country's entire population, and the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC) data from 2002 based on this program were used for this study. The NHIS-NSC is a stratified random sample of 1,025,340 subjects selected from around 46 million Koreans. We evaluated annual survival trends using the Kaplan-Meier test. Analyses of the relationship between survival and patient and hospital characteristics were performed using Cox regression analyses. Employing a multivariate model, variables were selected using the forward selection method to consider the multicollinearity of variables. A total of 32,553 patients admitted to an ICU between 2002 and 2013 were identified among the eligible beneficiaries. The number of patients who had histories of ICU admission steadily increased throughout the study period, and patients older than 80 years constituted a progressively increasing proportion of ICU admissions, from 7.3% in 2002 to 16.9% in 2007 to 23.1% in 2013. The mean number of mechanical equipment items applied consistently increased, while no difference was observed in the trend for overall 1-year survival in patients following ICU treatment across the study period: the 1-year survival rate ranged from 66.7% (year 2003) to 64.2% (year 2010). Advanced age, cancer, renal failure, pneumonia, and influenza were all associated with heightened risk of mortality within 1 year. Our results should prove useful to older patients and their clinicians in their decisions regarding whether to seek ICU care, with the goals of improving the end-of life care and optimizing resource utilization.

Dammarenediol-II production confers TMV tolerance in transgenic tobacco expressing Panax ginseng dammarenediol-II synthase.

Panax ginseng is one of the famous medicinal plants. Ginsenosides, a class of tetracyclic triterpene saponins, are mainly responsible for its pharmacological activity. Most ginsenosides are composed of dammarenediol-II aglycone with various sugar moieties. Dammarenediol-II synthase is the first enzyme in the biosynthesis of ginsenosides. Here, we report that transgenic tobacco expressing the P. ginseng dammarenediol-II synthase gene (PgDDS) produced dammarenediol-II, and conferred resistance to Tobacco mosaic virus (TMV). Upon infection with TMV, lesions developed more rapidly in transgenic tobacco plants, and their size was smaller than those of wild-type plants. Transgenic tobacco plants showed a low level of both the viral titer and mRNA accumulation of TMV coat protein (CP) compared with the wild type. The production of dammarenediol-II in transgenic tobacco stimulated the expression of tobacco pathogenesis-related genes (PR1 and PR2) under both virus-untreated and -treated conditions. When the leaves of wild-type plants were inoculated with a mixture of TMV and dammarenediol-II, the leaves exhibited a reduced viral concentration and TMV-CP expression than those receiving TMV treatment alone. When the leaves of P. ginseng were infected with TMV, transcription of PgDDS was significantly increased. Transgenic P. ginseng plants harboring a ß-glucuronidase (GUS) gene driven by the PgDDS promoter were constructed. The GUS expression was activated when the transgenic ginseng plants were treated with TMV. These results indicate that the medicinally important dammarenediol-II can be ectopically produced in tobacco, and the production of dammarenediol-II in tobacco plants allows them to adopt a viral defense system.

Enhanced triterpene and phytosterol biosynthesis in Panax ginseng overexpressing squalene synthase gene.

Roots of Panax ginseng, one of the most famous medicinal plants, contain various phytosterols and bioactive triterpene saponins (ginsenosides). In P. ginseng, phytosterols and triterpenes share the common biosynthetic intermediate, squalene. Here, we investigate the regulatory role of Panax ginseng squalene synthase (PgSS1) on the biosynthesis of phytosterols and triterpene saponins. PgSS1 transcripts are expressed ubiquitously in the various plant tissues, but higher in shoot apex and root. The transcript levels of PgSS1 increased markedly in the adventitious roots during 12- to 96-h period after metyl jasmonate (MeJA) treatment; MeJA treatment induced the activation of the transcripts of squalene epoxidase (SE), beta-amyrin synthase (bAS), but not cycloartenol synthase (CAS). Unlike MeJA treatment, overexpression of PgSS1 in adventitious roots of transgenic P. ginseng was followed by the up-regulation of all the downstream genes tested, such as SE, bAS, and CAS. The enhanced activity of PgSS1 enzyme resulted in remarkable increase of phytosterols as well as ginsenoside contents. These results demonstrate that PgSS1 is a key regulatory enzyme not only for phytosterol but also for triterpene biosynthesis and overexpressing of PgSS1 confers the hyperproduction of triterpene saponins to P. ginseng.