Development and Evaluation of a Post-Traumatic Growth Program for Teachers Victimized by Students or Parents in South Korea: A Quasi-Experimental Study.

This quasi-experimental, nonequivalent control group study developed an eight-session post-traumatic growth program for teachers who had experienced violence from students and/or parents and examined its effects on rumination, burnout, and post-traumatic growth. A convenience sample was recruited from 11 elementary schools in Jeonbuk province, South Korea. The experimental group (n = 27) participated in bi-weekly sessions over four weeks, whereas the control group (n = 27) read educational materials on post-traumatic growth during the same period. The experimental group exhibited significantly greater decreases in intrusive rumination and higher post-traumatic growth than the control group. The program could be an effective intervention to assist traumatized teachers.

Evaluation of residual level and distribution characteristics of organochlorine pesticides in agricultural soils in South Korea.

In this study, we evaluated the residual levels and distribution characteristics of 10 organochlorine pesticides (OCPs) in the soil of agricultural lands (paddy field, vegetable field, and orchard, n = 150) nationwide. As a result of the investigation, 3-10 types of OCPs were detected in combination in 144 locations (96%) of the total 150 locations. Among those OCPs, dichlorodiphenyltrichloroethane (DDT) and endosulfan were detected in high amounts. The geometric mean concentrations of DDT and endosulfan were ∑DDT 0.31 ng g-1 (ND-2187.18 ng g-1) and ∑endosulfan 0.33 ng g-1 (ND-312.68 ng g-1), respectively. OCP concentrations were generally higher in orchards than in other agricultural fields due to a large amount of pesticides used. DDT in two orchards was detected at 2187.18 ng g-1 and 1061.78 ng g-1, exceeding the levels stated in the Canadian DDT Soil Quality Guidance (SQG, 700 ng g-1). The result of applying the isomer ratio to evaluate the recent or past use of DDT, endosulfan, and hexachlorocyclohexane (HCH), which had a high detection rate, showed that it could be attributable to historical usage. DDT and HCH showed statistically similar residual distribution patterns; however, endosulfan did not show a clear correlation with DDT and HCH due to the effect of its recent use. Thus, the results of evaluation of OCP residual levels and distribution characteristics can be used for the soil management policy of OCPs in agricultural lands in Korea.

Regeneration of a full-thickness defect of rotator cuff tendon with freshly thawed umbilical cord-derived mesenchymal stem cells in a rat model.

BACKGROUND: It is difficult to immediately use mesenchymal stem cells (MSCs) for the patient with rotator cuff disease because isolation and culture time are required. Thus, the MSCs would be prepared in advanced in cryopreserved condition for an "off-the-shelf" usage in clinic. This study investigated the efficacy of freshly thawed MSCs on the regeneration of a full-thickness tendon defect (FTD) of rotator cuff tendon in a rat model. METHODS: We evaluated morphology, viability, and proliferation of cultured umbilical cord-derived MSCs (C-UC MSCs) and freshly thawed umbilical cord-derived MSCs (T-UC MSCs) at passage 10 in vitro. In animal experiments, we created a FTD in the supraspinatus of rats and injected the injured tendon with saline, cryopreserved agent (CPA; control), C-UC MSCs, and T-UC MSCs, respectively. Two and 4 weeks later, macroscopic, histological, biomechanical, and cell trafficking were evaluated. T test and ANOVA were used with SPSS. Differences with p < .05 were considered statistically significant. RESULTS: T-UC MSCs had fibroblast-like morphology and showed greater than 97% viability and stable proliferation comparable to the C-UC MSCs at passage 10. In animal experiments, compared with the control group, the macroscopic appearance of the T-UC MSCs was more recovered at 2 and 4 weeks such as inflammation, defect size, neighboring tendon, swelling/redness, the connecting surrounding tissue and slidability. Histologically, the nuclear aspect ratio, orientation angle of fibroblasts, collagen organization, and fiber coherence were improved by 33.33%, 42.75%, 1.86-fold, and 1.99-fold at 4 weeks, and GAG-rich area decreased by 88.13% and 94.70% at 2 and 4 weeks respectively. Further, the T-UC MSCs showed enhanced ultimate failure load by 1.55- and 1.25-fold compared with the control group at both 2 and 4 weeks. All the improved values of T-UC MSCs were comparable to those of C-UC MSCs. Moreover, T-UC MSCs remained 8.77% at 4 weeks after injury, and there was no significant difference between C-UC MSCs and T-UC MSCs. CONCLUSIONS: The morphology, viability, and proliferation of T-UC MSCs were comparable to those of C-UC MSCs. Treatment with T-UC MSCs could induce tendon regeneration of FTD at the macroscopic, histological, and biomechanical levels comparable to treatment with C-UC MSCs.

A cross-sectional study on the association between vitamin D levels and caries in the permanent dentition of Korean children.

BACKGROUND: A recent study in Canada reported that vitamin D deficiency is associated with dental caries. Because Koreans have been reported to be deficient in vitamin D, we investigated the relationship between dental caries and reduced serum vitamin D levels in Korean children. The purpose of this study was to analyze the relationships between blood vitamin D [25(OH)D] concentrations and dental caries in the permanent dentition of Korean children. METHODS: Data were collected from the Korea National Health and Nutrition Examination Survey performed in 2008-2013. A total of 1688 children (10-12 years of age) were enrolled. Vitamin D intake was measured through analysis of 25-hydroxy vitamin D [25(OH)D] levels. Caries experience in permanent dentition was assessed using the decay-missing-filled teeth (DMFT) index and decayed-missing-filled (DMF) rate. Statistical analyses included complex samples Chi-square tests, complex samples logistic regression analyses, and Pearson's correlations. RESULTS: The group with 25(OH) D levels lower than 50 nmol/L had a higher proportion of children with caries in the permanent dentition and permanent first molar than the group with 25(OH)D levels of 50 nmol/L or more. When external factors, such as sex, were controlled, 25(OH)D levels were not significantly correlated with caries, but were significantly correlated with first molar caries. Children with 25(OH)D levels lower than 50 nmol/L were 1.295 times more likely to have first molar caries than those with 25(OH)D levels of 50 nmol/L or more. Additionally, 25(OH)D levels and DMFT were negatively correlated; however, the degree of correlation was not strong. CONCLUSIONS: The association between 25(OH)D and dental caries is still not clear. However, our findings suggested that vitamin D insufficiency may be a risk factor for dental caries.

Fisetin inhibits matrix metalloproteinases and reduces tumor cell invasiveness and endothelial cell tube formation.

Matrix metalloproteinases (MMPs) play an important role in tissue remodeling during normal physiological situations and pathological implications such as tumor invasion and metastasis. MMP inhibitors were screened from extracts of medicinal herbs by an enzymatic assay using the MMP-14 catalytic domain. Among samples tested, a methanol extract of the root of Dalbergia odorifera T. CHEN (Leguminosae) showed the strongest inhibitory activity. The inhibitory component was purified through fractionation methods and identified as fisetin, abundant in many fruits and vegetables. In addition to inhibition of MMP-14, fisetin inhibits MMP-1, MMP-3, MMP-7, and MMP-9, more efficiently than a naturally occurring MMP inhibitor tetracycline. Fisetin dose-dependently inhibits proliferation of fibrosarcoma HT-1080 cells and human umbilical vascular endothelial cells (HUVECs), MMP-14-mediated activation of proMMP-2 in HT-1080 cells, invasiveness of HT-1080 cells, and in vitro tube formation of HUVECs. Therefore, fisetin could be valuable as a chemopreventive agent against cancer and a lead compound for development of therapeutic MMP inhibitors.

The degree of bacterial contamination while performing spine surgery.

STUDY DESIGN: Prospective experimental study. PURPOSE: To evaluate bacterial contamination during surgery. OVERVIEW OF LITERATURE: The participants of surgery and ventilation system have been known as the most significant sources of contamination. METHODS: Two pairs of air culture blood agar plate for G(+) bacteria and MacConkey agar plate for G(-) bacteria were placed at 3 different locations in a conventional operation room: in the surgical field, under the airflow of local air conditioner, and pathway to door while performing spine surgeries. One pair of culture plates was retrieved after one hour and the other pair was retrieved after 3 hours. The cultured bacteria were identified and number of colonies was counted. RESULTS: There was no G(-) bacteria identified. G(+) bacteria grew on all 90 air culture blood agar plates. The colony count of one hour group was 14.5±5.4 in the surgical field, 11.3±6.6 under the local air conditioner, and 13.1±8.7 at the pathway to the door. There was no difference among the 3 locations. The colony count of 3 hours group was 46.4±19.5, 30.3±12.9, and 39.7±15.2, respectively. It was more at the surgical field than under the air conditioner (p=0.03). The number of colonies of one hour group was 13.0±7.0 and 3 hours group was 38.8±17.1. There was positive correlation between the time and the number of colonies (r=0.76, p=0.000). CONCLUSIONS: Conventional operation room was contaminated by G(+) bacteria. The degree of contamination was most high at the surgical field. The number of bacteria increased right proportionally to the time.

Apolipoprotein A-IV is a novel substrate for matrix metalloproteinases.

Screening of matrix metalloproteinase (MMP)-14 substrates in human plasma using a proteomics approach previously identified apolipoprotein A-IV (apoA-IV) as a novel substrate for MMP-14. Here, we show that among the tested MMPs, purified apoA-IV is most susceptible to cleavage by MMP-7, and that apoA-IV in plasma can be cleaved more efficiently by MMP-7 than MMP-14. Purified recombinant apoA-IV (44-kDa) was cleaved by MMP-7 into several fragments of 41, 32, 29, 27, 24, 22 and 19 kDa. N-terminal sequencing of the fragments identified two internal cleavage sites for MMP-7 in the apoA-IV sequence, between Glu(185) and Leu(186), and between Glu(262) and Leu(263). The cleavage of lipid-bound apoA-IV by MMP-7 was less efficient than that of lipid-free apoA-IV. Further, MMP-7-mediated cleavage of apoA-IV resulted in a rapid loss of its intrinsic anti-oxidant activity. Based on the fact that apoA-IV plays important roles in lipid metabolism and possesses anti-oxidant activity, we suggest that cleavage of lipid-free apoA-IV by MMP-7 has pathological implications in the development of hyperlipidemia and atherosclerosis.

A study on Korean nursing students' educational outcomes.

The purpose of this study was to describe outcome indicators of nursing education including critical thinking, professionalism, leadership, and communication and to evaluate differences among nursing programs and academic years. A descriptive research design was employed. A total of 454 students from four year baccalaureate (BS) nursing programs and two three-year associate degree (AD) programs consented to complete self-administered questionnaires. The variables were critical thinking, professionalism, leadership and communication. Descriptive statistics, χ(2)-test, t-tests, ANOVA, and the Tukey test were utilized for the data analysis. All the mean scores of the variables were above average for the test instruments utilized. Among the BS students, those in the upper classes tended to attain higher scores, but this tendency was not identified in AD students. There were significant differences between BS students and AD students for the mean scores of leadership and communication. These findings suggested the need for further research to define properties of nursing educational outcomes, and to develop standardized instruments for research replication and verification.