Economic burden attributable to Clostridioides difficile infections in South Korea: a nationwide propensity score-matched study.

BACKGROUND: Clostridioides (Clostridium) difficile is an important pathogen that causes diarrhoea in patients who take antibacterial drugs. Considering the limited medical resources, it is necessary to prioritize the management of threats caused by antibiotic use and the spread of germs, but there are little available data, especially for C. difficile infections in South Korea. AIMS: In this study, we analysed the hospital length of stay (LOS) and the increase in medical costs due to C. difficile infections. METHODS: Propensity score-matched experimental (hospitalized patients with C. difficile infection)-control (hospitalized patients without C. difficile infection) studies were conducted to estimate the increase in the LOS and medical costs associated with C. difficile infections. The data were obtained from the National Health Insurance Service-National Sample Cohort from 2006 to 2015. Reliable results were obtained by actively calibrating various confounding variables of demographic characteristics, disease severity, and information on healthcare facilities. FINDINGS: The C. difficile-attributable increase in LOS and hospitalization costs were 36.9 days and 8298 USD, respectively, per infection case. CONCLUSION: This study quantified the considerable burden associated with C. difficile infections in South Korea.

Probiotics, prebiotics, synbiotics and insulin sensitivity.

Animal studies indicate that the composition of gut microbiota may be involved in the progression of insulin resistance to type 2 diabetes. Probiotics and/or prebiotics could be a promising approach to improve insulin sensitivity by favourably modifying the composition of the gut microbial community, reducing intestinal endotoxin concentrations and decreasing energy harvest. The aim of the present review was to investigate the effects of probiotics, prebiotics and synbiotics (a combination of probiotics and prebiotics) on insulin resistance in human clinical trials and to discuss the potential mechanisms whereby probiotics and prebiotics improve glucose metabolism. The anti-diabetic effects of probiotics include reducing pro-inflammatory cytokines via a NF-κB pathway, reduced intestinal permeability, and lowered oxidative stress. SCFA play a key role in glucose homeostasis through multiple potential mechanisms of action. Activation of G-protein-coupled receptors on L-cells by SCFA promotes the release of glucagon-like peptide-1 and peptide YY resulting in increased insulin and decreased glucagon secretion, and suppressed appetite. SCFA can decrease intestinal permeability and decrease circulating endotoxins, lowering inflammation and oxidative stress. SCFA may also have anti-lipolytic activities in adipocytes and improve insulin sensitivity via GLUT4 through the up-regulation of 5'-AMP-activated protein kinase signalling in muscle and liver tissues. Resistant starch and synbiotics appear to have favourable anti-diabetic effects. However, there are few human interventions. Further well-designed human clinical studies are required to develop recommendations for the prevention of type 2 diabetes with pro- and prebiotics.

The contribution of arachidonate 15-lipoxygenase in tissue macrophages to adipose tissue remodeling.

Cellular plasticity in adipose tissue involves adipocyte death, its clearance, and de novo adipogenesis, enabling homeostatic turnover and adaptation to metabolic challenges; however, mechanisms regulating these serial events are not fully understood. The present study investigated the roles of arachidonate 15-lipoxygenase (Alox15) in the clearance of dying adipocytes by adipose tissue macrophages. First, upregulation of Alox15 expression and apoptotic adipocyte death in gonadal white adipose tissue (gWAT) were characterized during adipose tissue remodeling induced by ß3-adrenergic receptor stimulation. Next, an in vitro reconstruction of adipose tissue macrophages and apoptotic adipocytes recapitulated adipocyte clearance by macrophages and demonstrated that macrophages co-cultured with apoptotic adipocytes increased the expression of efferocytosis-related genes. Genetic deletion and pharmacological inhibition of Alox15 diminished the levels of adipocyte clearance by macrophages in a co-culture system. Gene expression profiling of macrophages isolated from gWAT of Alox15 knockout (KO) mice demonstrated distinct phenotypes, especially downregulation of genes involved in lipid uptake and metabolism compared to wild-type mice. Finally, in vivo ß3-adrenergic stimulation in Alox15 KO mice failed to recruit crown-like structures, a macrophage network clearing dying adipocytes in gWAT. Consequently, in Alox15 KO mice, proliferation/differentiation of adipocyte progenitors and ß3-adrenergic remodeling of gWAT were impaired compared to wild-type control mice. Collectively, our data established a pivotal role of Alox15 in the resolution of adipocyte death and in adipose tissue remodeling.

The preventive effects of lifestyle intervention on the occurrence of diabetes mellitus and acute myocardial infarction in metabolic syndrome.

OBJECTIVES: Metabolic syndrome (MS), as a precursor of diabetes mellitus (DM) and cardiovascular disease, is increasing steadily worldwide. We examined the preventive effects of lifestyle intervention on the occurrence of DM and acute myocardial infarction (AMI) in MS. STUDY DESIGN: Observational study on disease occurrence after lifestyle intervention. METHODS: The lifestyle intervention was administered to subjects with MS participating in a metropolitan lifestyle intervention program for 1 year. The same numbers of non-participating age- and sex-matched subjects with MS were randomly extracted from national health examination data. After intervention or examination, new occurrences of hypertension, DM, and AMI were identified through the national health insurance claims data during 1 year. For DM and AMI, multivariate logistic regression analysis for the factors affecting each disease was performed. RESULTS: In the intervention group and the control group (14,918 in each group), the occurrence of hypertension was 555 (6.07%) and 751 (8.33%), the occurrence of DM was 324 (2.55%) and 488 (3.89%), the occurrence of dyslipidemia was 321 (2.59%) and 373 (2.72%), and the occurrence of AMI was 13 (0.09%) and 26 (0.17%), respectively. In multivariate logistic regression analysis, adjusted odds ratios for intervention were 0.752 (95% confidence interval [CI]: 0.644-0.879) and 0.499 (95% CI: 0.251-0.992) for DM and AMI, respectively, indicating that lifestyle intervention has a preventive effect. CONCLUSIONS: Lifestyle intervention in MS has preventive effects on the occurrence of DM and AMI, and long-term follow-up is needed to evaluate these preventive effects in more detail.

Suppression of T-cell proliferation by and B7-H1 expression on human liver-derived stem cells.

BACKGROUND: Many types of stem cells have been widely used for the treatment of liver diseases. The therapeutic effect of stem cells is predominantly based on the immune regulatory properties of these cells. METHODS: We isolated human liver stem cells (HLSCs), which are considered intrahepatic stem cells, and examined their suppression of T-cell proliferation induced by phytohemagglutinin. RESULTS: HLSCs inhibited phytohemagglutinin-induced T-cell proliferation not only in direct co-culture but also in indirect co-culture in a cell number-dependent manner. That is, T-cell proliferation was substantially inhibited by cell-to-cell contact regardless of soluble factor(s). B7-H1, a co-inhibitory molecule that relies on cell-to-cell contact, was found to be constitutively expressed at low levels on HLSCs. Furthermore, its expression was upregulated moderately by tumor necrosis factor-α and dramatically by interferon-γ. CONCLUSIONS: These results suggest that HLSCs would have therapeutic effects through T-cell suppression in acute liver diseases.

Favorable effect of dietary vitamin C on bone mineral density in postmenopausal women (KNHANES IV, 2009): discrepancies regarding skeletal sites, age, and vitamin D status.

UNLABELLED: Dietary vitamin C intake showed significant positive associations with BMD in postmenopausal women, especially with vitamin D deficiency. INTRODUCTION: Although there is a positive role of vitamin C in osteoblastogenesis, debate remains about the contribution of vitamin C to bone mineral density (BMD) in humans. METHODS: Data were derived from the Fourth Korean National Health and Nutrition Examination Survey. Dietary information was assessed using a 24-h dietary recall questionnaire. BMD was measured by dual-energy X-ray absorptiometry at the lumbar and hip. RESULTS: A total of 1,196 postmenopausal women aged 50 years and older were stratified into tertiles by daily dietary vitamin C intake. After adjusting for traditional confounders, dietary vitamin C intake tertile was significantly positively associated with BMD at all sites (R = 0.513 for lumbar spine (LS) and R = 0.657 for femoral neck (FN), P < 0.05 for each). The subjects with osteoporosis had significantly lower dietary vitamin C intake than did subjects without osteoporosis (74.4 ± 66.2 vs 94.1 ± 78.6 mg/day for LS and 65.5 ± 56.6 vs 94.3 ± 79.2 mg/day for FN, respectively, P < 0.001). The multiple-adjusted odds ratio for osteoporosis for dietary vitamin C <100 mg/day was 1.790 (95 % CI 1.333-2.405, P < 0.001). However, the significant association between vitamin C intake and BMD was only observed in subjects with vitamin D deficiency and aged 50-59 years or >70 years. CONCLUSION: Dietary vitamin C intake was positively associated with BMD in postmenopausal women, and inadequate vitamin C intake could increase the risk of osteoporosis.

Group B streptococcal bacteremia in non-pregnant adults: results from two Korean centers.

Patients with liver cirrhosis (LC) have impaired immunity and are, thus, predisposed to infection. Few studies have attempted to evaluate group B streptococcal (GBS) bacteremia in LC patients. A retrospective study of patients with GBS bacteremia was performed at the Dongguk University Ilsan Hospital and National Health Insurance Service Ilsan Hospital over a 13-year period (October 2000 to July 2013). During the study period, 97 patients with GBS bacteremia were enrolled. The median age of the patients was 67 years and 54 % were men. Among them, 23 (24 %) patients were classified as LC patients. The 30-day mortality rate of LC patients was significantly higher than that of patients with other diseases (26 % vs. 8 %, p = 0.03). The multivariate analysis indicated that LC was associated with an increased risk of 30-day mortality [hazard ratio (HR) 5.0; 95 % confidence interval (CI) 1.53-16.3; p = 0.008], as well as age (HR 1.07; 95 % CI 1.03-1.13; p = 0.02) and high Pitt bacteremia score (HR 1.23; 95 % CI 1.02-1.46; p = 0.03). The probability of survival at day 30 was significantly different for the Child-Pugh class C and the Child-Pugh classes A or B (44 % vs. 93 %, respectively; p = 0.01 by the log-rank test). The mortality rates of LC patients with GBS bacteremia were significantly higher than those of patients with other diseases. The severity of hepatic dysfunction plays an important role in the development of adverse events. Cirrhosis-specific scores such as the Child-Pugh class might be useful for predicting the prognosis of GBS bacteremia in LC patients.

Evaluation of anatomic landmarks for axillary nerve block in the quadrilateral space.

BACKGROUND: Axillary nerve block (ANB) was recently introduced along with suprascapular nerve block as an alternative to inter-scalene brachial plexus block for post-operative pain control. However, the methods for performing ANB are variable. We studied the relationship between surface anatomy and the location of the axillary nerve in the quadrilateral space to ensure a technically safe and simple ANB. METHODS: Eighty-eight shoulders were included. All measurements were performed with the subjects seated and the shoulders in a neutral position. We located the posterior circumflex humeral artery (PCHA) using a vascular Doppler system and named this point 'AN'. We used this point to locate the axillary nerve, since this nerve is generally present with the PCHA in the quadrilateral space. We then examined the relationship between surface anatomic landmarks and AN. The depth of the medial side of the humerus at the AN (AN depth), which is at the lateral border of the quadrilateral space, was measured using ultrasonography. RESULTS: AN was located on the line between the posterolateral corner of the acromion (Ac) and the axillary fold (Axf) (Ac-Axf) in 77% of shoulders. The ratio of the distance from Ac to AN (Ac-AN) to Ac-Axf in all shoulders was 0.6 [standard deviation (SD), 0.1]. AN depth was 4.0 (SD, 0.5) cm in men and 3.6 (SD, 0.4) cm in women. CONCLUSION: Knowledge of the relationship between surface anatomy and AN, as well as estimated AN depth may aid in locating the axillary nerve in the quadrilateral space.

Written informed consent for living kidney donors: practices and compliance with CMS and OPTN requirements.

We sought to assess how written informed consent practices for candidate living kidney donors have changed over the last 5 years and to assess compliance with Centers for Medicare and Medicaid (CMS) and Organ Procurement and Transplantation Network (OPTN) regulations that took effect in 2007. We requested evaluation consent forms from US centers that performed >5 living kidney transplants during the prior year (n = 184). We received 148 consent forms; each was reviewed for information provided and inclusion of CMS- and OPTN-required elements. We found that nearly all transplant centers now obtain written consent for living kidney donor evaluation. However, most centers' evaluation consent forms do not include all CMS and OPTN requirements. Multiple items balancing donor and recipient interests and confidentiality were omitted. In addition, information about payment for routine follow-up care, complications related to surgery and other health problems following surgery were highly variable and frequently ambiguous. As centers revise their consent forms to address the 2013 OPTN policies, our findings may help them identify areas of potential deficiency. We propose that UNOS develop a uniform donor evaluation consent form to improve the clarity, consistency and efficiency of living donor consent.

Replication of Caucasian loci associated with bone mineral density in Koreans.

SUMMARY: Most bone mineral density (BMD) loci were reported in Caucasian genome-wide association studies (GWAS). This study investigated the association between 59 known BMD loci (+200 suggestive SNPs) and DXA-derived BMD in East Asian population with respect to sex and site specificity. We also identified four novel BMD candidate loci from the suggestive SNPs. INTRODUCTION: Most GWAS have reported BMD-related variations in Caucasian populations. This study investigates whether the BMD loci discovered in Caucasian GWAS are also associated with BMD in East Asian ethnic samples. METHODS: A total of 2,729 unrelated Korean individuals from a population-based cohort were analyzed. We selected 747 single-nucleotide polymorphisms (SNPs). These markers included 547 SNPs from 59 loci with genome-wide significance (GWS, p value less than 5 × 10(-8)) levels and 200 suggestive SNPs that showed weaker BMD association with p value less than 5 × 10(-5). After quality control, 535 GWS SNPs and 182 suggestive SNPs were included in the replication analysis. RESULTS: Of the 535 GWS SNPs, 276 from 25 loci were replicated (p < 0.05) in the Korean population with 51.6 % replication rate. Of the 182 suggestive variants, 16 were replicated (p < 0.05, 8.8 % of replication rate), and five reached a significant combined p value (less than 7.0 × 10(-5), 0.05/717 SNPs, corrected for multiple testing). Two markers (rs11711157, rs3732477) are for the same signal near the gene CPN2 (carboxypeptidase N, polypeptide 2). The other variants, rs6436440 and rs2291296, were located in the genes AP1S3 (adaptor-related protein complex 1, sigma 3 subunit) and RARB (retinoic acid receptor, beta). CONCLUSION: Our results illustrate ethnic differences in BMD susceptibility genes and underscore the need for further genetic studies in each ethnic group. We were also able to replicate some SNPs with suggestive associations. These SNPs may be BMD-related genetic markers and should be further investigated.

Needs regarding care and factors associated with unmet needs in disease-free survivors of surgically treated lung cancer.

BACKGROUND: To evaluate the long-term needs of lung cancer survivors and to explore factors associated with unmet need. PATIENTS AND METHODS: We recruited lung patients treated with curative surgery from 2001 through 2006 at two centers in Korea. Needs in the domains of information, supportive care, education and counseling, and socioeconomic support were measured. We selected the four most frequently reported items of unmet need among 19 items in four domains. RESULTS: The most frequently reported unmet needs were Complementary and alternative medicine (CAM) and folk remedies (59.8%) in the Information domain, Counseling and treatment of depression and anxiety (63.5%) in the Supportive care domain, diet, exercise and weight control (55.1%) in the Education and counseling domain and Financial support (90.4%) in the socioeconomic support domain. Unmet needs for psychological treatment was significantly greater in participants who were employed (adjusted odds ratio [aOR], 2.25; 95% confidential interval [CI], 1.12 to 4.53). Unmet needs for diet, exercise and weight control were significantly greater in participants who had not received chemotherapy (aOR, 1.76; 95% CI, 1.09 to 2.85). Unmet need for financial support was greater in participants who were married (aOR, 4.14, 95%CI, 1.12 to 15.22) and those who had not received chemotherapy (aOR, 5.91, 95%CI, 1.91 to 18.31). CONCLUSION: There were substantial unmet needs for information regarding psychological support, education for diet and exercise, and financial support among lung cancer survivors.

Effect of complementary and alternative medicine on the survival and health-related quality of life among terminally ill cancer patients: a prospective cohort study.

BACKGROUND: We evaluated whether complementary and alternative medicine (CAM) use influenced outcomes [survival and health-related quality of life (HRQOL)] of cancer patients whose condition had just been judged terminal. PATIENTS AND METHODS: From July 2005 to October 2006, we conducted a prospective cohort study of 481 terminally ill cancer patients at 11 university hospitals and the National Cancer Center in Korea. We assessed how the use of CAM affected HRQOL and survival. RESULTS: In a follow-up of 481 patients and 163.8 person-years, we identified 466 deceased cases. On multivariate analyses, CAM users did not have better survival compared with nonusers [adjusted hazard ratio (aHR), 0.91; 95% confidence interval (CI) 0.74-1.10]. Among mind-body interventions, prayer showed significantly worse survival (aHR, 1.56; 95% CI, 1.00-2.43). Clinically, CAM users reported significantly worse cognitive functioning (-11.6 versus -1.3; P < 0.05) and fatigue (9.9 versus -1.0; P < 0.05) than nonusers. Compared with nonusers in subgroup analysis, users of alternative medical treatments, prayer, vitamin supplements, mushrooms, or rice and cereal reported clinically significant worse changes in some HRQOL subscales. CONCLUSION: While CAM did not provide any definite survival benefit, CAM users reported clinically significant worse HRQOLs.

The phenotypic characteristic of liver-derived stem cells from adult human deceased donor liver.

Liver transplantation is the only effective treatment for end-stage liver disease. Because of the limited donor availability, attention has been focused on the possibility to restore liver mass and function through cell transplantation. Stem cells are a promising source for liver repopulation after cell transplantation, but whether or not the adult liver contains hepatic stem cells is highly controversial. Several studies have suggested the presence of stem cells in the adult normal human liver. However, a population with stem cell properties has not yet been isolated. The purpose of this study was to identify and characterize progenitor cells in normal adult human liver. We isolated and expanded human liver stem cells (HLSCs) from a donated liver not suitable for liver transplantation or characterizing them by fluorescence-activated cell sorter, polymerase chain reaction, and immunofluorescence assay. HLSCs expressed the mesenchymal stem cell markers CD29, CD73, CD44, CD90, CD105, and CD166 but not the hematopoietic stem cell markers CD34, CD45, and CD117. HLSCs were also positive for vimentin and nestin, a stem cell marker. The absence of staining for cytokeratin-19, CD117, and CD34 indicated that HLSCs were not oval stem cells. In addition, HLSCs expressed CD26, and in a small percentage of cells, cytokeratin-8 and cytokeratin-18, indicating a partial commitment to hepatic cells. We concluded that HLSCs expressed several mesenchymal but not hematopoietic stem cell markers as well as CD26 and CK18, indicating a partial commitment to hepatic cells.

Differentiation and major histocompatibility complex antigen expression in human liver-derived stem cells.

Stem cells are a promising source for liver repopulation after cell transplantation, but whether the adult liver contains hepatic stem cells is controversial. The purpose of this study was to characterize the properties and expression profile of major histocompatibility complex (MHC) antigens on the surface of human-derived stem cells. Human liver-derived stem cells (HLSC7) were isolated from the nontumorous tissue of a patient who underwent a resection of an hepatic hemangioendothelioma. We characterized HLSC7 using a fluorescence-activated cell sorter, polymerase chain reactions, and immunofluorescence assays. HLSC7 expressed mesenchymal but not hematopoietic stem cell markers. HLSC7 underwent osteogenic, chondrogenic, and hepatogenic differentiation when cultured in appropriate differentiation media. However, HLSC7 did not differentiate into adipocytes. In addition, HLSC7 did not express MHC class II (HLA-DP, -DQ, and -DR) antigens. However, they did express MHC class I antigens. These results suggest that human liver-derived stem cells express MHC class I antigens and thus may be rejected on transplantation. Therefore, in addition to studies on stem cell differentiation, one must overcome immunologic barriers for successful clinical application of this therapy.

Live cell-imaging perfusion culture system of liver sinusoidal endothelial cells to mimic stem cell engraftment in liver.

Hepatocyte and various hepatic stem cell transplantations have been studied as alternative therapies to orthotopic liver transplantation for liver injury. The engraftment of transplanted cells into the parenchyma requires transmigration through sinusoidal endothelial cells (SECs), the only cellular barrier. In this study, we constructed a SEC-imaging perfusion culture system that mimics sinusoids with respect to hemorheologic properties. SECs were successfully maintained for 24 hours. Human liver stem cells (HLSCs) were used as a model of transplanted cells for in vitro engraftment to SECs under perfusion culture conditions. Conditions of high shear stress perfusion with 0.34 dyne/cm(2) significantly reduced cell adhesion in contrast to lower shear stress conditions of 0.1 and 0.03 dyne/cm(2). Among the biologic perfusion fluids, namely, fetal bovine serum (FBS), pig plasma, and 5% human albumin solution, HLSCs showed significantly greater attachment to SECs when perfused with FBS, which is well known to contain abundant amounts of adhesion molecules. This biomimetic SEC perfusion culture system may provide a useful tool to study engraftment mechanisms and to evaluate the effects of various enhancers as an alternative to animal models.

The influence of hospital volume and surgical treatment delay on long-term survival after cancer surgery.

BACKGROUND: We conducted a population-based retrospective cohort study to investigate the influence of hospital volume, delay of surgery, and both together on the long-term survival of postoperative cancer patients. METHODS: Using information from the Korea Central Cancer Registry from 2001 through 2005 and the National Health Insurance claim database, we determined survival for 147 682 patients who underwent definitive surgery for any of six cancers. RESULTS: Regardless of cancer site, surgical patients in low- to medium-volume hospitals showed significantly worse survival [adjusted hazard ratio (aHR) = 1.36-1.86] than those in high-volume hospitals in multivariable analyses. Among the latter, treatment delays > 1 month were not associated with worse survival for stomach, colon, pancreatic, or lung cancer but were for rectal [aHR = 1.28; 95% confidence interval (CI), 1.17-1.40] and breast (aHR = 1.59; 95% CI, 1.37-1.84) cancer. For patients in low- to medium-volume hospitals, treatment delay was associated with worse survival for all types of cancer (aHR = 1.78-3.81). CONCLUSION: Our findings suggest that the effect of hospital volume and surgical treatment delay on overall survival of cancer patients should be considered in formulating or revising national health policy.