The Feasibility of Fast, Four-Dimensional Computed Tomography-Based O-Ring Linac Plans for Stereotactic Body Radiotherapy in Patients with Poor Performance Status

PURPOSE/OBJECTIVE(S)

As patients with poor performance status cannot endure long treatment times, it can lead to unplanned and prolonged radiation treatment or discontinuation of treatment. Moreover, prolonged radiation treatment appears to negatively affect survival for patients. We aimed to verify the feasibility of fast 4DCT-based O-ring linear accelerator (LINAC) treatment in lung 4D stereotactic body radiotherapy (SBRT).

MATERIALS/METHODS

This study included data of 38 patients who received lung 4D-SBRT. Gating20-70% plans were based on 4DCT data obtained at phase values ranging from 20-70% using a C-arm LINAC. Non-GatingFB plans were retrospectively established based on 4DCT data obtained at phase values of 0-90% using an O-ring LINAC. The prescribed dose of 4,800 cGy was delivered to PTV in four fractions. The conformity index (CI), homogeneity index (HI), and gradient measurement (GM) of the PTV were analyzed to compare dosimetric data between Gating20-70% and Non-GatingFB plans. Organs at risks (OARs) were analyzed in accordance with the RTOG 0915 protocol. Treatment delivery time and total monitor units (MU) were analyzed to compare the efficiency of treatment delivery. Statistical comparisons were performed using the Wilcoxon signed-rank test (p<0.05).

RESULTS

For the PTV, there was no significant difference in the CI or HI between Gating20-70% and Non-GatingFB plans (CI: 1.337±0.137, 1.335±0.174, HI: 0.939±0.015, 0.939±0.016, all at p>0.05). However, there was a significant difference in GM between Gating20-70% and Non-GatingFB plan (1.528±0.206 cm, 1.381±0.222 cm, p<0.001). For OARs, all plans met the criteria for dose constraint. There was a significant difference between Gating20-70% and Non-GatingFB plans except in the spinal cord. In particular, D1000cc and D1500cc values for the ipsilateral lung for Gating20-70% plans were 31.6% and 59.9% lower than those for Non-GatingFB plans (D1000cc: 50.780±132.061 cGy, 34.755±102.480 cGy, p<0.001, D1500cc: 6.641±14.598 cGy, 2.666±7.926 cGy, p<0.001). Treatment delivery time was 92% longer for Gating20-70% plans than for Non-GatingFB plans (5.0±0.4 min, 9.6±3.3 min, p = 0.043). The total MU value for Gating20-70% plans was 9.6% higher than that for Non-GatingFB plans (3665.8±230.7, 4016±236.9, p = 0.039).

CONCLUSION

When compared to OARs both plans were acceptable per RTOG-0915 protocol, but significant differences were between Non-GatingFB and Gating20-70% plans. However, treatment delivery time of Non-GatingFB plans decreased by 47.9% than Gating20-70% plans. We verified the feasibility of fast 4DCT-based O-ring LINAC treatment for patients who cannot endure long treatment times due to poor performance status in lung 4D-SBRT. In further study, we will analyze dosimetric differences and treatment delivery efficiency considering tumor motion according to tumor location.

P1249Prognostic impact of sarcopenia on major adverse cardiovascular outcomes in coronary artery disease patients undergoing successful percutaneous coronary intervention

Background

Sarcopenia is an emerging marker of frailty. Its prognostic impact on atherosclerotic cardiovascular disease (ASCVD) requires further investigation.

Purpose

We investigated the long-term prognostic impact of computed tomography (CT)-determined sarcopenia in patients with coronary artery disease (CAD).

Methods

Total 475 CAD patients those who underwent successful percutaneous coronary intervention (PCI) and performed CT scan within 30 days of PCI were enrolled. The cross-sectional area of skeletal muscle at the first lumbar vertebra (L1) level was measured. Sarcopenia was defined as L1 skeletal muscle index of less than 34.60 cm2/m2 for men and of less than 25.90 cm2/m2 for women. Primary outcome was 3-year all-cause mortality and secondary outcome was 3-year major adverse cardiovascular event (MACE), a composite of all-cause mortality, any myocardial infarction, and repeat revascularization.

Results

Sarcopenia was present in 214 (45.1%) of 475 patients. The incidence of 3-year all-cause mortality and MACE was significantly higher in patients with sarcopenia than in those without sarcopenia (17.7% vs. 5.7%, p<0.001; and 35.0% vs. 11.2%, p<0.001, respectively). In the fully adjusted multivariable analysis, sarcopenia was an independent predictor of higher risk of 3-year all-cause mortality (odds ratio [OR]: 2.98; 95% confidence interval [CI]: 1.35 to 6.58, p=0.007) and MACE (OR: 4.39; 95% CI: 2.49 to 7.73, p<0.001). The results were consistent after propensity-score matched analysis with 100 pairs of study population (C-statistics = 0.868).

Kaplan–Meier analysis of 3-year outcomes Overall population PSM population Sarcopenia (n=214) No sarcopenia (n=261) Log-rank p-value Sarcopenia (n=100) No sarcopenia (n=100) Log-rank p-value All-cause mortality 36 (17.7) 14 (5.7) <0.001 19 (20.0) 7 (7.7) 0.013 Non-fatal MI 12 (6.6) 5 (2.0) 0.021 6 (7.0) 2 (2.3) 0.134 Repeat revascularization 32 (20.3) 14 (6.2) <0.001 17 (23.3) 8 (8.0) 0.027 Total MACEs 68 (35.0) 27 (11.2) <0.001 36 (39.3) 14 (15.4) 0.001 Data are expressed as n (%). MACE = major adverse cardiovascular event; MI = myocardial infarction; PSM = propensity-score matched.

Clinical impact of sarcopenia on CAD

Conclusion

Sarcopenia is a useful predictor of adverse clinical outcomes in patients with CAD undergoing PCI. CT-determined sarcopenia may further aid in risk stratification and decision-making for patients with established ASCVD.

Acknowledgement/Funding

National Research Foundation of Korea (NRF-2016R1A2B3013825), Ministry of Future Creation and Science of Korea (2018K000255)

P4339Reference values for cardiorespiratory fitness in healthy Koreans: compared to western nations and nomogram

Introduction

Cardiorespiratory Fitness (CRF), defined as the integrated ability to properly oxygenate skeletal muscles during physical activity, is associated with a high risk of cardiovascular disease and all-cause mortality. The reference range for CRF may differ among nations, with Asians under-represented in previous data.

Purpose

In this study, we sought to establish reference values of CRF for Asians using a recent Korean cohort.

Methods

We analyzed 2646 healthy Korean adults recently enrolled in the Korea Institute of Sports Science Fitness Standards (KISS FitS) project with estimated maximal oxygen uptake (VO2max) values during treadmill test. Patients with cardiovascular or renal disease, systemic infection, pregnant women and those with orthopedic injuries unable to measure physical fitness were excluded. Age-specific mean VO2max values were compared with those from recent American, Norwegian, Danish cohorts and old Korean data.

Results

Age-specific reference values for healthy Korean adults in this cohort were as shown (Table). We were able to draw a nomogram to predict exercise capacity for a given age and MET value (Figure). When compared to other countries, less CRF reduction by aging was seen in Asians than in other Westerners. When compared to old Korean data from the 1980s, values were similar after adjustment for difference in methods, except for those under 30 years old which were decreased.

Exercise capacity of healthy Korean Men Women Age VO2max (ml/kg/min) N P-value for trend Age VO2max (ml/kg/min) N P-value for trend 19–29 42.3±6.3± 209 <0.01 19–29 34.3±4.3± 110 <0.01 30–39 42.0±5.0± 170 39–39 32.2±4.5± 211 40–49 41.4±5.6± 238 40–49 30.8±4.6± 284 50–59 38.0±5.7± 274 50–59 28.3±4.6± 367 60–69 32.4±6.2± 134 60–69 26.0±5.7± 336 70–79 27.2±5.6± 83 70–79 23.9±4.4± 195 >80 24.1±4.0± 11 >80 21.0±3.7± 24 Total 38.6±7.4± 1119 Total 28.5±5.8 1527 Data are presented as mean ± standard deviation. VO2max, maximal oxygen uptake; N, number.

Nomogram of exercise capacity in Koreans

Conclusions

While there was no significant change in CRF over time in the same ethnic group, there was a clear inter-ethnic difference. CRF should be assessed according to ethnic or national standards, and it is necessary to establish a reference for each nation or ethnicity with periodic updates.

Acknowledgement/Funding

National Sports Promotion Fund of the Korea Sports Promotion Foundation in 2015

P2501Validation of FRIEND and ACSM equations for cardiorespiratory fitness: comparison to direct measurement in male CAD patients

Introduction

Cardiorespiratory fitness (CRF) is associated with a high risk of cardiovascular disease and all-cause mortality. The regression equation of American College of Sports Medicine (ACSM) was a preferred method for estimating maximal oxygen consumption (VO2max). It is well-known that CRF is overestimated in ACSM equation. Recently, Kokkinos reported more precise equation from the Fitness Registry and the Importance of Exercise National Database (FRIEND). Both equations were made from western healthy people.

Purpose

In this study, we compared VO2max estimated by ACSM and FRIEND equations to VO2max directly measured in male coronary artery disease (CAD) patients.

Methods

We analyzed 103 male CAD patients who underwent percutaneous coronary intervention and who participated in cardiac rehabilitation between June 2015 and December 2018. VO2max was directly measured by the gas exchange analysis during treadmill test with modified Bruce protocol. Exclusive criteria were pulmonary disease, chronic kidney disease on hemodialysis, malignancy, peripheral artery disease, insufficient cardiopulmonary exercise test and orthopedic injuries. Directly measured VO2max were compared to ACSM and FRIEND equations.

Results

Age-specific VO2max values, which were directly measured from male CAD patients, were shown in Table. Smaller CRF difference was shown in FRIEND equation than ACSM equation. Compared to the measured value, CRF estimated by ACSM equation was overestimated by 22%, but the one estimated by FRIEND equation had only 2% gap. Figure presents Bland-Altman plots. ACSM equation had the higher bias (5.52ml/kg/min) compared with FRIEND equation (0.200ml/kg/min).

Comparison table of VO2max estimated by ACSM and FRIEND equations with directly measured VO2max in male CAD patients Age Number VO2max (ml/kg/min) Measured ACSM % predicted FRIEND % predicted 30–39 4 29.5 ± (6.6) 35.7 ± (6.1) 122.3 ± (8.5) 29.1 ± (4.3) 100.1 ± (8.7) 40–49 20 29.1 ± (5.1) 35.7 ± (5.4) 123.6 ± (11.1) 29.1 ± (3.8) 101.2 ± (9.5) 50–59 32 25.6 ± (4.3) 31.5 ± (5.1) 123.8 ± (10.1) 26.2 ± (3.6) 103.2 ± (8.5) 60–69 27 26.0 ± (5.1) 31.1 ± (2.6) 120.5 ± (12.6) 25.9 ± (4.0) 100.8 ± (10.5) 70–79 18 21.2 ± (6.0) 26.8 ± (5.4) 123.2 ± (14.8) 22.8 ± (3.9) 105.2 ± (12.0) >80 2 25.0 ± (10.1) 22.8 ± (2.6) 97 ± (28.9) 19.9 ± (1.9) 85.1 ± (27.0) Total 103 25.7 ± (5.6) 31.4 ± (6.0) 122.2 ± (12.4) 26.1 ± (4.3) 102.1 ± (10.4) Data are presented as mean ± (standard deviation).

Bland-Altman plots

Conclusions

FRIEND equation can estimate CRF more accurately than ACSM equation, even in Asian patients with CAD.

4098Reduced skeletal muscle mass is associated to worsened long-term clinical outcomes in patients with coronary artery disease: a quantitative analysis by computed tomography

Background

Sarcopenia is closely associated to poor clinical outcomes in patients with atherosclerotic cardiovascular disease (ASCVD). However, it is unclear whether the skeletal muscle mass at baseline has quantitative effect on future cardiovascular outcomes.

Purpose

We investigated the quantitative effect of skeletal muscle mass on future cardiovascular outcomes in patients with coronary artery disease (CAD).

Methods

Total 475 patients those who underwent successful percutaneous coronary intervention (PCI) for CAD and performed computed tomography (CT) scan within 30 days of PCI were enrolled. The cross-sectional area of skeletal muscle at the first lumbar vertebra (L1) level was measured. Whole study population was divided into 4 groups according to the sex-specific quartiles of skeletal muscle index (SMI). Primary outcome was all-cause mortality and secondary outcome was major adverse cardiovascular event (MACE) within 3 years of follow-up.

Results

Mean follow-up duration was 4.11±3.02 years and average time period from the date of PCI to CT scan was −3.33±11.72 days. The incidence of 3-year all-cause mortality (23.2% vs. 9.9% vs. 6.6% vs. 4.4%, p<0.001) and MACE (42.9% vs. 24.0% vs. 14.3% vs. 6.2%, p<0.001) was significantly higher in the group of lower quartiles of L1-SMI. In the fully adjusted multivariable analysis, lower quartiles of L1-SMI was an independent predictor of higher risk of all-cause mortality and MACE (lowest vs. highest quartile; OR: 4.90, 95% CI: 1.54 to 15.5, p=0.007; and OR: 12.3, 95% CI: 4.99 to 30.4, p<0.001, respectively).

Results of 3-year clinical outcomes SMI Q1 (n=124) SMI Q2 (n=116) SMI Q3 (n=112) SMI Q4 (n=123) Log-rank p-value All-cause mortality 27 (23.2) 11 (9.9) 7 (6.6) 5 (4.4) <0.001 Non-fatal MI 9 (8.7) 3 (3.0) 2 (2.0) 3 (2.6) 0.038 Repeat revascularization 20 (24.9) 15 (15.2) 7 (7.1) 4 (3.8) <0.001 Total MACEs 47 (42.9) 26 (24.0) 15 (14.3) 7 (6.2) <0.001 Data are expressed as n (%). MACE = major adverse cardiovascular event; MI = myocardial infarction; SMI = skeletal muscle index; Q = quartile.

Impact of reduced skeletal muscle on CAD

Conclusion

Skeletal muscle mass at baseline is a powerful predictor of future adverse clinical outcomes in patients with CAD undergoing successful PCI. Quantitative assessment of skeletal muscle mass at L1 level by CT scan provides prognostic implication for future cardiovascular risk stratification.

Acknowledgement/Funding

National Research Foundation of Korea (NRF-2016R1A2B3013825), Ministry of Future Creation and Science of Korea (2018K000255)

P2523Hand grip strength as a predictor of exercise capacity in coronary heart disease

A recent study has shown that quadriceps strength can be used to predict the level of exercise capacity in patients with coronary heart disease (CHD). We investigated whether the relationship between muscular strength and exercise capacity is also observed with hand grip strength (HGS). We studied 443 participants (age, 61.8±11.2 y; 77.7% male) who underwent coronary intervention and participated in cardiac rehabilitation between 2015 and 2018. Participants were assessed for grip strength, measured using a Jamar dynamometer. Logistic regression was used to assess the relationship between various clinical measures (HGS, age, sex, etc) with the distance walked on a 6-minute walk test (6MWT) and maximal oxygen uptake (VO2max). HGS was significantly related to distance walked on the 6MWT (r=0.435, p<0.001). It was the only predictor of all exercise capacity categories, and one of the strongest predictors of each exercise capacity category. A HGS of 25.5% of body weight predicted an achievement of a 200 m walk on the 6MWT (positive predictive value = 0.95). However, HGS less than 35.5% of body weight predicted that 500m could not be done in 6 minutes (negative predictive value = 0.97). This trend was also observed in the subgroups in which VO2max was measured. This study demonstrates that HGS is associated with exercise capacity in CHD and can be used to predict the level of exercise capacity. These findings may contribute to setting the recommended level of daily activity as well as the level of cardiac rehabilitation in CHD.

Logistic regression models for different levels of exercise capacity Level of exercise capacity B±S.E p-value Odd ratio 95% CI Distance of 6MWT   200 m Grip strength 0.054±0.014 <0.001 1.056 1.027–1.086   300 m Grip strength 0.042±0.009 <0.001 1.042 1.024–1.062   400 m Grip strength 0.047±0.011 <0.001 1.048 1.026–1.070   500 m Grip strength 0.051±0.016 0.001 1.053 1.021–1.086 VO2max level   4 METs Grip strength 0.054±0.010 <0.001 1.056 1.036–1.076   6 METs Grip strength 0.059±0.011 <0.001 1.061 1.039–1.083   8 METs Grip strength 0.081±0.015 <0.001 1.085 1.053–1.117   10 METs Grip strength 0.113±0.049 0.019 1.12 1.019–3.232 Data are presented as mean ± standard deviation (SD). 6MWT, 6-minute walk test; STEMI, ST-Elevation Myocardial Infarction; SE, standard error; CI, confidence interval; VO2max, Maximal Oxygen uptake; METs, Metabolic equivalents.

Factors influencing obesity among preschoolers: multilevel approach

BACKGROUND

Childhood obesity is a complex and multifaceted problem involving interactions among child, family and community environment.

AIM

The purpose of this study was to examine the contributing factors to early childhood obesity within a multilevel context, including child and family, childcare setting and community.

METHODS

A cross-sectional, quantitative research design was employed. A total of 129 preschoolers and their parents in northwest Florida participated in this study. Child height and weight were measured, and body mass index (BMI) was calculated. Parents and directors of preschools completed survey questionnaires to assess child/family, childcare setting and community factors, respectively. Hierarchical multiple regression was used to evaluate the association of each level of factors with child BMI z-score.

RESULTS

Twenty-one per cent of children were overweight or obese (≥85th BMI percentile). In hierarchical multiple regression, household income, parent beliefs, attitudes and practices for child feeding, family obesogenic environment, child routines (screen time on weekends, sleep hours, bedtime) and physical activity environment were significantly related to child BMI z-score.

CONCLUSIONS

The findings of this study provide a broader understanding of factors that influence child BMI z-score. Shaping a non-obesogenic environment by establishing healthy routines for children in the home, childcare setting and community is essential in childhood obesity prevention.

IMPLICATIONS FOR NURSING PRACTICE AND HEALTH POLICY

Paediatric nurses should routinely assess accurate parental perception of child weight, feeding style and child routines in well-child care visits. Healthcare professionals and health policymakers should enact policies that build a healthy environment for preschoolers in their childcare setting and community.

Correction: The Rho/ROCK pathway for lysophosphatidic acid-induced proteolytic enzyme expression and ovarian cancer cell invasion

The original version of this article contained an error in the published figures Fig 2 and Fig 3f, where the information was inadvertently duplicated. This error does not alter the conclusions of the paper. The corrected figures are published in this correction notice. The authors sincerely apologize for this error.

Correction: RCP induces Slug expression and cancer cell invasion by stabilizing β1 integrin

Following the publication of this article the authors noted that images were inadvertently duplicated in Fig. 1b. The corrected Fig. 1 can be found in the associated Correction. The conclusions of this paper are not affected. The authors sincerely apologize for this error. This error has not been corrected in the HTML or PDF of the original Article.

Development and preliminary evaluation of culturally specific web-based intervention for parents of adolescents

WHAT IS KNOWN ON THE SUBJECT?: Problematic parent-child relationships have been identified as one of the main predictors of adolescents' mental health problems, but there are few existing interventions that address this issue. The format and delivery method of existing interventions for parents are relatively inaccessible for parents with full-time jobs and families living in rural areas. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: The newly developed 'Stepping Stone' culturally specific web-based intervention, which is intended to help Korean parents of adolescents to acquire both knowledge and communication and conflict management skills, was found to be feasible and well-accepted by parents. This study enabled us to identify areas for improvement in the content and format of the intervention and strategies. This will potentially increase effect sizes for the outcome variables of parents' perception and behaviours. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: This web-based intervention could be delivered across diverse settings, such as schools and community mental health centers, to increase parents' knowledge of adolescent's mental health and allow for early detection of mental health problems. Mental health nurses working in schools may spend a significant amount of time addressing students' mental health issues; thus, this web-based intervention could be a useful resource to share with parents and children. In this way, the mental health nurses could facilitate parental engagement in the intervention and then help them to continue to apply and practice the knowledge and skills obtained through the program.

ABSTRACT

Introduction There is a need for accessible, culturally specific web-based interventions to address parent-child relationships and adolescents' mental health. Aims This study developed and conducted a preliminary evaluation of a 4-week web-based intervention for parents of adolescents aged 11 to 16 years in Korea. Methods We used a two-group, repeated measures, quasi-experimental study design to assess the feasibility of developing and implementing a web-based intervention for parents. Descriptive statistics, chi-square and t tests, and mixed effect modeling were used for data analysis. Results The intervention and 1-month follow-up survey were completed by 47 parents in the intervention group and 46 parents in the attention control (AC) group. The intervention was found to be feasible and well-accepted by parents. Discussion This culturally specific web-based intervention is a useful tool for knowledge dissemination among large numbers of parents. Areas for improvement in the content and format of the intervention and strategies to elicit significant parent-child interactions are provided. Implications for practice and conclusion The intervention could be disseminated in collaboration with mental health nurses working in schools to facilitate parents' participation.

Long-term control of diabetes in immunosuppressed nonhuman primates (NHP) by the transplantation of adult porcine islets

Pig islets are an alternative source for islet transplantation to treat type 1 diabetes (T1D), but reproducible curative potential in the pig-to-nonhuman primate (NHP) model has not been demonstrated. Here, we report that pig islet grafts survived and maintained normoglycemia for >6 months in four of five consecutive immunosuppressed NHPs. Pig islets were isolated from designated pathogen-free (DPF) miniature pigs and infused intraportally into streptozotocin-induced diabetic rhesus monkeys under pretreatment with cobra venom factor (CVF), anti-thymocyte globulin (ATG) induction and maintenance with anti-CD154 monoclonal antibody and low-dose sirolimus. Ex vivo expanded autologous regulatory T cells were adoptively transferred in three recipients. Blood glucose levels were promptly normalized in all five monkeys and normoglycemia (90-110 mg/dL) was maintained for >6 months in four cases, the longest currently up to 603 days. Intravenous glucose tolerance tests during the follow-up period showed excellent glucose disposal capacity and porcine C-peptide responses. Adoptive transfer of autologous regulatory T cells was likely to be associated with more stable and durable normoglycemia. Importantly, the recipients showed no serious adverse effects. Taken together, our results confirm the clinical feasibility of pig islet transplantation to treat T1D patients without the need for excessive immunosuppressive therapy.

The LIM-only transcription factor LMO2 determines tumorigenic and angiogenic traits in glioma stem cells

Glioblastomas (GBMs) maintain their cellular heterogeneity with glioma stem cells (GSCs) producing a variety of tumor cell types. Here we interrogated the oncogenic roles of Lim domain only 2 (LMO2) in GBM and GSCs in mice and human. High expression of LMO2 was found in human patient-derived GSCs compared with the differentiated progeny cells. LMO2 is required for GSC proliferation both in vitro and in vivo, as shRNA-mediated LMO2 silencing attenuated tumor growth derived from human GSCs. Further, LMO2 is sufficient to induce stem cell characteristics (stemness) in mouse premalignant astrocytes, as forced LMO2 expression facilitated in vitro and in vivo growth of astrocytes derived from Ink4a/Arf null mice and acquisition of GSC phenotypes. A subset of mouse and human GSCs converted into vascular endothelial-like tumor cells both in vitro and in vivo, which phenotype was attenuated by LMO2 silencing and promoted by LMO2 overexpression. Mechanistically, the action of LMO2 for induction of glioma stemness is mediated by transcriptional regulation of Jagged1 resulting in activation of the Notch pathway, whereas LMO2 directly occupies the promoter regions of the VE-cadherin gene for a gain of endothelial cellular phenotype. Subsequently, selective ablation of human GSC-derived VE-cadherin-expressing cells attenuated vascular formation in mouse intracranial tumors, thereby significantly prolonging mouse survival. Clinically, LMO2 expression was elevated in GBM tissues and inversely correlated with prognosis of GBM patients. Taken together, our findings describe novel dual roles of LMO2 to induce tumorigenesis and angiogenesis, and provide potential therapeutic targets in GBMs.

Effects of Coconut Materials on In vitro Ruminal Methanogenesis and Fermentation Characteristics

The objective of this study was to evaluate the in vitro effects of coconut materials on ruminal methanogenesis and fermentation characteristics, in particular their effectiveness for mitigating ruminal methanogenesis. Fistulated Holstein cows were used as the donor of rumen fluid. Coconut materials were added to an in vitro fermentation incubated with rumen fluid-buffer mixture and timothy substrate for 24 h incubation. Total gas production, gas profiles, total volatile fatty acids (tVFAs) and the ruminal methanogens diversity were measured. Although gas profiles in added coconut oil and coconut powder were not significantly different, in vitro ruminal methane production was decreased with the level of reduction between 15% and 19% as compared to control, respectively. Coconut oil and coconut powder also inhibited gas production. The tVFAs concentration was increased by coconut materials, but was not affected significantly as compared to control. Acetate concentration was significantly lower (p<0.05), while propionate was significantly higher (p<0.05) by addition of the coconut materials than that of the control. The acetate:propionate ratio was significantly lowered with addition of coconut oil and coconut powder (p<0.05). The methanogens and ciliate-associated methanogens in all added coconut materials were shown to decrease as compared with control. This study showed that ciliate-associated methanogens diversity was reduced by more than 50% in both coconut oil and coconut powder treatments. In conclusion, these results indicate that coconut powder is a potential agent for decreasing in vitro ruminal methane production and as effective as coconut oil.

PCDD and PCDF concentrations in a traffic tunnel environment

In an effort to understand the fundamental aspects of air quality in traffic tunnel environments, field campaigns were conducted to measure polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and other important pollutants within two traffic tunnels in Nam San (NS) and Hong Ji (HJ) in Korea in 2009 and 2010. The mean concentrations of ∑PCDD/Fs (in fg/m(3)) at the two tunnel sites were 1270 (± 880) and 1200 (± 810), respectively. These values were moderately lower than those measured at a non-tunnel urban background site (1350 (± 780) fg/m(3))--selected as a reference in this study. In addition, seasonal patterns of dioxin concentrations were clearly evident at the traffic tunnels like the urban reference site, showing higher levels during the winter (and spring) than the summer (and fall). The observed seasonal variations were driven by changes in the concentrations of ∑PCDF congeners, while ∑PCDD concentrations showed little seasonality. The results of our study suggest that there is no significant difference in source characteristics between the two investigated tunnel sites and urban location, although the role of gasoline and diesel fueled vehicles are considered as the major source in determining the PCDDs and PCDF levels in a tunnel environment. However, given the relative increase in other important ambient pollutant (e.g. PM10) concentrations over ∑PCDD/Fs in tunnel air (compared to urban background air), the balance of sources in tunnels is clearly different from those in urban air overall.

An investigation into the relationship between the major chemical components of particulate matter in urban air

Particulate matter (PM) generally comprises such chemical components as inorganic ions, organic carbon (OC), elemental carbon (EC), and metals. In terms of environmental studies, these major chemical components of particulate matter (MCP) are important in understanding PM distribution, behaviors and source apportionment. In this study, the MCP fractions of total suspended particles (TSP) were measured at an urban residential area in Seoul, Korea from February to December in 2009. The behavior of each individual MCP was studied in order to explain their relationship to environmental conditions and sources. The MCP measured during this study period was able to account between 54% (spring) to 67% (fall) of total TSP composition. During the study period, it was found that the TSP sampled comprised mostly: anions, OC, cations, EC, and metals in decreasing order of abundance. Although such relative ordering seems to remain fairly constant over time, the relative balance of this relationship may be altered by variations in environmental conditions.

Comprehensive monitoring of drinking well water quality in Seoul metropolitan city, Korea

In this research, the quality of drinking well waters from 14 districts around Seoul metropolitan city, Korea was assessed by measuring a number of parameters with established guideline (e.g., arsenic, fluoride, nitrate nitrogen, benzene, 1,2-dichloroethene, dichloromethane, copper, and lead) and without such criteria (e.g., hardness, chloride ion, sulfate ion, ammonia nitrogen, aluminum, iron, manganese, and zinc). Physical parameters such as evaporation residue (or total dissolved solids) and turbidity were also measured. The importance of each parameter in well waters was examined in terms of the magnitude and exceedance frequency of guideline values established by international (and national) health agencies. The results of this study indicate that among the eight parameters with well-established guidelines (e.g., WHO), arsenic and lead (guideline value of 0.01 mg L(-1) for both) recorded the highest exceedance frequency of 18 and 16 well samples ranging in 0.06-136 and 2-9 mg L(-1), respectively. As such, a number of water quality parameters measured from many well waters in this urban area were in critical levels which require immediate attention for treatment and continuous monitoring.

Monitoring of polyaromatic hydrocarbons and volatile organic compounds in two major traffic tunnels in Seoul, Korea

To describe the fundamental aspects of air quality in tunnel environments, field campaigns were conducted to measure polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and some criteria pollutants from two tunnel sites of Nam San (NS) and Hong Ji (HJ) gates in Seoul, Korea. The total PAH values (ngm(-3)) for the NS tunnel (137.8 +/- 10.9) were notably higher than the HJ counterpart (91.3 +/- 7.82), while the total VOC exhibited a reversed pattern with a notable enhancement in the HJ tunnel (178.5 +/- 174.7 ppbC) relative to the NS tunnel (112.5 +/- 64.1 ppbC). A line of evidence, including the molecular diagnostic ratios of PAHs, indicates the relative dominance of diesel vehicles in the NS tunnel compared to the HJ site. The PAHs with high ring numbers (n > 6, such as benzo(g, h, i)perylene and indeno(1,2,3-cd)pyrene) were preferentially enriched in the particle phase, whereas their low ring number counterparts (n = 2-3) were in the gas phase. The results of our study suggest the possibility that the relative source processes for each tunnel site are characterized by the relative dominance of either diesel (NS) or gasoline-powered vehicles (HJ).

Volatile Organic Compounds in Ambient Air at Four Residential Locations in Seoul, Korea

To investigate the environmental behavior of volatile organic compounds (VOCs) in urban areas, their concentrations were measured at four urban monitoring sites (namely, N, S, E, and W) in Seoul, Korea (February to December 2009). A total of 27 compounds were quantified that consist of four chemical groups: aromatic (AR), halogenated aromatic, halogenated paraffin, and halogenated olefin. Results were evaluated by focusing on these four functional groups just mentioned and their summation term as total VOC (TVOC) along with several individual species (mainly AR species, that is, benzene, toluene, ethylbenzene, and xylene). The highest concentration of chemical groups was found from AR (71.1±42.1 ppbC), while that for individual species confirmed the dominance of toluene (7.48±3.88 ppb). The analysis of spatial distribution indicated that high TVOC levels were recorded at sites N and W, while it was not so significant such as S and E in terms of TVOC budget. Seasonal variation of these VOCs was characterized by the peak values in December to reflect the combined effects of pronounced source activities and meteorological conditions. Analysis of spatial variations in VOC levels between the four urban sites indicated that their distributions are tightly affected by local source processes in each area.

HIV-related symptoms and patient clusters among Chileans living with HIV

Identifying both Human immunodeficiency virus (HIV)-related and co-morbid symptoms experienced by people living with HIV (PLWH) who are receiving antiretroviral therapy (ART) treatment is a major challenge for healthcare providers globally. Yet, little research to date has examined the symptoms of illness experienced by PLWH including patients living in Central and South American. To address this gap, this study was designed to identify symptoms of HIV by socio-demographic and/or clinical characteristics among Chilean patients living with the virus. A convenience sample of 209 Chilean PLWH was recruited from an outpatient clinic in Santiago, Chile. A structured interview was used to elicit socio-demographic information and HIV symptoms status. Additional clinical information was obtained through a review of the participants' medical records. Results show that patients' most commonly reported HIV-related symptoms were fear/worries (66%), anxiety (52%), gas/bloating (50%), and thirst (50%). Multivariate analysis revealed a positive association between the number of reported HIV-related symptoms and number of years living with HIV. Having completed college was negatively associated with number of symptoms. Latent class analysis indicated that PLWH in the sample who had completed college were two times more likely to experience a mild intensity of HIV-related symptoms than their lesser educated counterparts. Similarly, logistic regression revealed that college-educated PLWH were twice as likely to be classified in the subgroup reporting mild intensity of symptoms than those who lacked a college degree. Overall, the study's results reveal that many Chilean PLWH, even those with high CD4 counts and low or undetectable viral loads, are not symptom free. The findings point to the need for clinicians to tailor a plan of care for individuals living with HIV that is based on their symptomatology.

Some insights into the relationship between urban air pollution and noise levels

The relationship between noise and air pollution was investigated in eight different districts across Seoul, Korea, between September and November 2010. The noise levels in each district were measured at both roadside and non-roadside locations. It was found that the maximum levels of noise were generally at frequencies of around 1000 Hz. The equivalent noise levels (L(eq)), over all districts, averaged 61.4 ± 7.36 dB which is slightly lower than the noise guidelines set by the World Health Organization (WHO) of 70 dB for industrial, commercial, traffic, and outdoor areas. Comparison of L(eq) levels in each district consistently indicates that noise levels are higher at roadside sites than non-roadside sites. In addition the relative dominance of noise during daytime as compared to nighttime was also apparent. Moreover, the results of an analysis relating sound levels with air pollutant levels indicate strongly that the correlation between these two parameters is the strongest at roadside sites (relative to non-roadside sites) and during nighttime (relative to daytime). The results of our data analysis point to a positive, but complex, correlation between noise levels and air pollution.

Association of hypertension with small, dense low-density lipoprotein in patients without metabolic syndrome

A higher proportion of small, dense low-density lipoprotein (sdLDL) is known to be associated with a high prevalence of cardiovascular disease in association with metabolic syndrome (MS). Hypertension (HTN) is one of the known risk factors for MS. However, whether HTN is associated with sdLDL in patients without MS is not yet clear. The lipid profiles, including low-density-lipoprotein (LDL) subfractions, of 383 consecutive subjects were evaluated. The patients without MS consisted of 198 hypertensive patients (non-MS/HTN group) and 108 normotensive subjects (non-MS/non-HTN group). The peak and mean particle diameter of LDL were measured by gradient gel electrophoresis. Plasma total cholesterol, LDL cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride (TG), HDL cholesterol/Apo A1, LDL-C/ApoB and Apo(A1, B, CII and E) levels did not differ between the non-MS/non-HTN and non-MS/HTN groups. When analyzing LDL subfraction, the absolute amount of patterns A and B was not different between the non-MS/non-HTN and non-MS/HTN groups. Compared with the non-MS/non-HTN groups, the proportion of sdLDL was higher in the non-MS/HTN group (37.7% versus 39.9%, P=0.046), but not significant after adjustment of waist circumference, serum TG, age and statin usage. The proportion of sdLDL to total LDL was higher in hypertensive subjects, even those without MS, than in normotensive subjects. However, this difference of LDL subfraction in hypertensive patients is associated with higher waist circumference, higher serum TG, older age and more statin usage. This result suggests that HTN may contribute to atherosclerosis and endothelial dysfunction with associated risk factors that influence LDL size.

Elevated levels of macrophage migration inhibitory factor in women with metabolic syndrome

Metabolic syndrome is a complex clinical disorder characterized by obesity, a disturbance of glucose metabolism, dyslipidemia, and hypertension, leading to increased cardiovascular risk. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine produced both by innate immune cells and by adipocytes, and it plays an important role in inflammatory and cardiovascular diseases. The goal of this study was to evaluate the expression of circulating MIF in patients with metabolic syndrome. A study was conducted involving 172 persons who attended the Jeju National University Hospital Health Promotion Center. Among the 172 subjects, 88 patients with metabolic syndrome and 84 healthy control subjects were included. Serum MIF levels were considerably higher in patients with metabolic syndrome than in healthy subjects (mean±SEM, 1413.0-pg/ml±102.6 vs. 1077.0-pg/ml±-91.3, p=0.016). Among the metabolic syndrome patients, MIF levels were significantly increased in women (1403.0-pg/ml±114.2 vs. 921.3 pg/ml±117.3, p=0.005), but not in men. Even after further linear regression adjustment for age and body mass index, the expression of MIF for women with metabolic syndrome was still clearly elevated when compared to healthy subjects (p=0.011). Circulating MIF concentrations showed a gender disparity between healthy and metabolic syndrome subjects. An elevation of systemic MIF in women with metabolic syndrome may contribute to pathogenesis of metabolic syndrome or to the development of metabolic syndrome-related diseases, such as atherosclerosis and type 2 diabetes mellitus.

The role of β-blockers in the management of hypertension: an Asian perspective

Following publication of the National Institute of Clinical Excellence (NICE) Guidelines in 2006, the use of β-blockers as first-line therapy in hypertension has been somewhat controversial. However, a recent reappraisal of the European Society of Hypertension guidelines highlights that these agents exhibit similar BP lowering efficacy to other classes of agents, prompting a re-examination of the utility of these agents in various patient populations. The authors felt that it is important to address this controversy and provide an Asian perspective on the place of β-blockers in current clinical practice and the benefits of β-blockade in selected patient populations. In addition to their use as a potential first-line therapy in uncomplicated hypertension, β-blockers have a particular role in patients with hypertension and comorbidities such as heart failure or coronary artery disease, including those who had a myocardial infarction. One advantage which β-blockers offer is the additional protective effects in patients with prior cardiovascular events. Some of the disadvantages attributed to β-blockers appear more related to the older drugs in this class and further appraisal of the efficacy and safety profile of newer β-blockers will lend support to the current guideline recommendations in Asian countries and encourage increased appropriate use of β-blockade in current clinical practice within Asia.

Lysophosphatidic acid augments human hepatocellular carcinoma cell invasion through LPA1 receptor and MMP-9 expression

Lysophosphatidic acid (LPA), produced extracellularly by autotaxin (ATX), has diverse biological activities implicated in tumor initiation and progression, including increasing cell survival, angiogenesis, invasion and metastasis. ATX, LPA and the matrix metalloproteinase (MMP)-9 have all been implicated in hepatocellular carcinoma (HCC) invasion and metastasis. We, thus sought to determine whether ATX with subsequent LPA production and action, including induction of MMP-9 could provide a unifying mechanism. ATX transcripts and LPA receptor type 1 (LPA1) protein are elevated in HCC compared with normal tissues. Silencing or pharmacological inhibition of LPA1 significantly attenuated LPA-induced MMP-9 expression and HCC cell invasion. Further, reducing MMP-9 activity or expression significantly inhibits LPA-induced HCC cell invasion, demonstrating that MMP-9 is downstream of LPA1. Inhibition of phosphoinositide-3 kinase (PI3K) signaling or dominant-negative mutants of protein kinase Cδ and p38 mitogen-activated protein kinase (MAPK) abrogated LPA-induced MMP-9 expression and subsequent invasion. We thus demonstrate a mechanistic cascade of ATX-producing LPA with LPA activating LPA1 and inducing MMP-9 through coordinate activation of the PI3K and the p38 MPAK signaling cascades, providing novel biomarkers and potential therapeutic targets for HCC.

Concentrations of TSP-bound metals in four urban residential locations in Seoul, Korea

Concentrations of 17 trace metals bound in total suspended particulate (TSP) were measured at four urban residential locations (Jong Ro [JR], Gwang Jin [GJ], Gang Seo [GS], and Yang Jae [YJ]) in Seoul, Korea from February to July 2009. The maximum concentrations of metals were recorded by Fe in the range of 2599 (JR) to 2914 ng m^-3 (GJ), while the least values were observed from Ag or Co with a few ng m^-3. The relative ordering of the mean concentration (ng m^-3) at these sites is generally found on the order of Fe > Zn > Ba > Mn > Pb > Cu > B > Cr > Ni > Sr >V > As > Li > Cd > Mo > Co > Ag or with a few exceptions (e.g., a reversal between Ba and Mn or between Ni and Sr). Calculation of the enrichment factor suggests the significant role of man-made processes on such metals as Cd, Zn, and Pb. Inspection of the temporal patterns indicates the peak occurrence of most metals during the spring season due in part to the Asian Dust (AD) event. However, according to the factor analysis, sources of these metals were dominated by both resuspended soil/road dust and the combustion of fossil fuels. The overall results of our study suggest that the interaction between the environmental conditions and roadside traffic activities are paramount in explaining the metal pollution in these urban residential areas.

Degradation of diethyl phthalate in treated effluents from an MBR via advanced oxidation processes: effects of nitrate on oxidation and a pilot-scale AOP operation

The major objective of this study was to delineate the oxidation of diethyl phthalate (DEP) in water, using bench-scale UV/H2O2 and O3/H2O2 processes, and to determine the effects of nitrate (NO(3-)-N, 5 mg L(-1)) on this oxidation. The oxidation of DEP was also investigated through a pilot-scale advanced oxidation process (AOP), into which a portion of the effluent from a pilot-scale membrane bioreactor (MBR) plant was pumped. The bench-scale operation showed that DEP could be oxidized via solely UV oxidation or O3 oxidation. The adverse effect of nitrate on the DEP oxidation was remarkable in the UV/H2O2 process, and the nitrate clearly reduced its oxidation. The adverse effect of nitrate on O3 oxidation was also observed. It was noted, however, that the nitrate clearly enhanced the DEP oxidation in the O3/H2O2 process. A series of pilot-scale AOP operations indicated that the addition of H2O2 enhanced DEP oxidation in both the UV/H2O2 and O3/H2O2 processes. No noticeable adverse effect of nitrate was observed in the NO(3-)-N concentration of about 6.0 mg L(-1), which was naturally contained in the treatment stream. About 52% and 61% of the DEP were oxidized by each of these two oxidation processes in this pilot-scale operation. Both the UV/H2O2 and O3/H2O2 processes appeared to be desirable alternatives for DEP oxidation in treatment effluent streams.

Impact of hypertension on coronary artery spasm as assessed with intracoronary acetylcholine provocation test

Both hypertension and coronary artery spasm (CAS) are associated with endothelial dysfunction. Thus, a higher incidence of CAS is expected in hypertensive patients. We evaluated the impact of hypertension on CAS with intracoronary acetylcholine (ACh) provocation test. A total of 986 patients (685 hypertensive patients vs 301 normotensive patients) who underwent coronary angiography with ACh provocation test were enrolled. ACh was injected into the left coronary artery in incremental doses of 20, 50 and 100 microg min(-1). Significant CAS was defined as a transient >70% luminal narrowing with concurrent chest pain and/or ST-segment changes. Although the incidences of significant ACh-induced CAS were similar between hypertensive and normotensive patients (35.8 vs 39.2%, P=0.303), multivariate logistic analysis showed that hypertension was negatively associated with ACh-induced CAS (odds ratio: 0.70, 95% confidence interval: 0.51-0.94, P=0.020). The angiographic characteristics of ACh-induced CAS were similar between these two groups. Subgroup analysis regarding the impact of the status of blood pressure control on CAS showed that hypertensive patients with controlled blood pressure had a significantly higher incidence of CAS than those with uncontrolled blood pressure (45.2 vs 27.9%, P<0.001), and that uncontrolled blood pressure was negatively associated with ACh-induced CAS (odds ratio: 0.56, 95% confidence interval: 0.40-0.79, P=0.001). In conclusion, despite the expected endothelial dysfunction, hypertension and uncontrolled blood pressure are negatively associated with CAS, suggesting that the mechanisms and risk factors of CAS may be significantly different from those of coronary artery disease.

Expert recommendations on the challenges of hypertension in Asia

A consensus meeting of leading Asian hypertension experts was held in January 2007 in Seoul, Korea, to discuss how to address the growing challenge of hypertension management in the region. This report summarises key recommendations from the group, including: raising public awareness about the impact of hypertension; improving physician education and training; increasing early detection, for example through routine blood pressure measurement; and development and adoption of pan-Asian treatment guidelines, which would greatly facilitate research into hypertension and its management. The group conclude that these challenges can only be met through a collaborative effort of government, healthcare professionals, food and healthcare industries, and patients and the public. Food and healthcare industries need to develop healthy foods and support healthy living programmes, while increasing research into antihypertensive medications in Asia. Government officials and policy makers need to be made aware of the value of investing in hypertension awareness, prevention and management programmes.

Implication of lipocalin-2 and visfatin levels in patients with coronary heart disease

OBJECTIVES

Visfatin and lipocalin-2 are novel adipokines associated with insulin resistance (IR) and obesity-related metabolic disorders. We compared lipocalin-2 and visfatin concentrations between patients with coronary heart disease (CHD) and control subjects and evaluated their association with cardiovascular risk factors.

METHODS

We examined serum visfatin, lipocalin-2 levels, and cardiovascular risk factors in 91 subjects (49 patients with angiographically confirmed CHD versus 42 age- and gender-matched control participants).

RESULTS

Circulating lipocalin-2 levels were significantly higher in patients with CHD compared with the control subjects (82.6+/-38.7 ng/ml versus 43.8+/-27.8 ng/ml; P<0.001). However, visfatin levels were not significantly different between patients with CHD and control subjects. Serum lipocalin-2 levels were positively associated with weight (r=0.26; P=0.036), fasting insulin (r=0.36; P=0.003), and IR (r=0.33; P=0.007), whereas these levels showed a negative correlation with high-density lipoprotein (HDL) cholesterol (r=-0.30; P=0.016) after adjustment for gender and body mass index. However, visfatin levels were not associated with any variables of the metabolic syndrome. The multiple regression analysis showed that lipocalin-2 levels were independently associated with HDL cholesterol and IR (R2=0.199). Furthermore, the multiple logistic regression analysis showed that systolic blood pressure, IR, and lipocalin-2 levels were independently associated with CHD.

CONCLUSIONS

Serum lipocalin-2 levels were significantly elevated in patients with CHD and were independently associated with CHD. The present findings suggest that the measurement of serum lipocalin-2 levels may be useful for assessing CHD risk.

The prevalence of and risk factors for erosive oesophagitis and non-erosive reflux disease: a nationwide multicentre prospective study in Korea

BACKGROUND

Prospective nationwide multicentre studies that have evaluated endoscopic findings and reflux symptoms using a well-designed questionnaire are very rare.

AIM

To compare the prevalence rates of and risk factors for erosive oesophagitis and non-erosive reflux disease (NERD) in the Korean population.

METHODS

A gastroscopic examination was performed on 25 536 subjects who visited 40 Healthcare Centers for a health check-up. A gastro-oesophageal reflux questionnaire and multivariate analysis were used to determine the risk factors for erosive oesophagitis and NERD.

RESULTS

2019 (8%) and 996 subjects (4%) had erosive oesophagitis and non-erosive reflux disease, respectively; only 58% of subjects with erosive oesophagitis had reflux symptoms. Multivariate analysis showed that the risk factors for erosive oesophagitis and NERD differed, i.e. those of erosive oesophagitis were male, a Helicobacter pylori eradication history, alcohol, body mass index > or =25 and hiatal hernia. In contrast, the risk factors for NERD were female, age <40 and > or =60 vs. 40-59 years, body mass index <23 and a monthly income <$1000, glucose > or =126 mg/dL, smoking, a stooping posture at work and antibiotic usage.

CONCLUSIONS

The prevalence rates of erosive oesophagitis and NERD were 8% and 4%, respectively, in Korean health check-up subjects. The risk factors for erosive oesophagitis and NERD were found to differ, which indicates that their underlying pathogeneses are distinct.

Advanced H2O2 oxidation for diethyl phthalate degradation in treated effluents: effect of nitrate on oxidation and a pilot-scale AOP operation

One of the objectives of this study was to delineate the effect of nitrate on diethyl phthalate (DEP) oxidation by conducting a bench-scale ultraviolet (UV)/H2O2 and O3/H2O2 operations as suggested in a previous study. We also aim to investigate DEP oxidation at various UV doses and H2O2 concentrations by performing a pilot-scale advanced oxidation processes (AOP) system, into which a portion of the effluent from a pilot-scale membrane bioreactor (MBR) plant was pumped. In the bench-scale AOP operation, the O3 oxidation alone as well as the UV irradiation without H2O2 addition could be among the desirable alternatives for the efficient removal of DEP dissolved in aqueous solutions at a low DEP concentration range of 85+/-15 microg/L. The adverse effect in the UV/H2O2 process was significantly greater than that in the UV oxidation alone, and its oxidation was almost halved by the nitrate. However, the nitrate clearly enhanced the DEP oxidation in the O3 oxidation and O3/H2O2 process. Especially, the addition of nitrate almost doubled the DEP oxidation efficiency in the O3/H2O2 process. The series of pilot-scale AOP operations confirmed that about 30-50% of DEP dissolved in the treated MBR effluent streams was, at least, oxidized by the O3 oxidation alone as well as the UV irradiation without H2O2 addition. The UV photolysis of H2O2 was most effective for DEP degradation with an H2O2 concentration of 40 mg/L at a UV dose of 500 mJ/cm2.

Myocardial bridging is related to endothelial dysfunction but not to plaque as assessed by intracoronary ultrasound

BACKGROUND

Myocardial bridge (MB) is characterised by focal compression of a coronary artery in systole by an overlying band of myocardium. Chronic compression and relaxation of the MB may produce endothelial dysfunction by direct stress.

OBJECTIVE

To determine whether MB alters endothelial function, thus influencing the plaque formation.

METHODS

128 patients (mean (SD) age 54.7 (10.9) years, 56 men) with typical angiographic systolic milking effects and >30% reduction in diameter of the coronary artery during systole after intracoronary nitrate (glyceryl trinitrate, 200 mug) infusion were studied. 231 control patients (mean (SD) age 52.9 (12.1) years, 111 men) without overt coronary artery disease including MB were also studied. Endothelial function was estimated by incremental acetylcholine (Ach) infusion into the left coronary ostium. Intracoronary ultrasound assessments were obtained in 74/128 patients with MB and 81/231 controls.

RESULTS

The mean (SD) vasoconstrictive response to maximal Ach was more pronounced at the bridging segments than at matched segments in controls (-71.9 (14.9) vs -30.3 (22.6), p = 0.009). Coronary vasoconstriction (>50%) to Ach was seen more often in the MB group than in controls (114/128 (89.1%) vs 81/231 (35.1%), p = 0.007). No significant correlation was found between the severity of MB and vasoconstriction in response to Ach. A typical half-moon phenomenon was seen in 71/74 (95.9%) cases of the MB group, but not in controls (p<0.001). Plaques at the bridging segments were absent in 67/74 (90.5%) and mild in 7/74 (9.5%) cases, as compared with those of matched segments of the left anterior descending coronary artery in controls (plaque burden 5.91 (1.37)% vs 24.71 (24.21)%, p = 0.002).

CONCLUSION

Despite the prominent relationship between MB and endothelial dysfunction, bridging segments are spared from atherosclerotic plaque formation.

Relationship between blood pressure parameters and pulse wave velocity in normotensive and hypertensive subjects: invasive study

Blood pressure (BP) is one of the most important contributing factors to pulse wave velocity (PWV), a classic measure of arterial stiffness. Although there have been many non-invasive studies to show the relation between arterial stiffness and BP, the results are controversial. The aim of this study is to evaluate the role of BP as an influencing factor on PWV using invasive method. We observed 174 normotensive and untreated hypertensive subjects using coronary angiography. Arterial stiffness was assessed through aorto-femoral PWV by foot-to-foot velocity method using fluid-filled system. And BP was measured by pressure wave at the right common femoral artery. From univariate analysis, age, diabetes mellitus (DM), hypertension, waist, waist-to-hip ratio, total cholesterol-to-high-density lipoprotein cholesterol ratio, systolic BP (SBP), pulse pressure (PP) and mean arterial pressure (MAP) showed significant association with PWV. To avoid multiple colinearity among SBP, PP and MAP, we performed multiple regression analysis predicting PWV thrice. Age, DM and each BP were significantly and consistently correlated to PWV. In the first and third modules, compared to age, SBP and MAP were less strong predictors, respectively. However, PP was the stronger predictor than age and DM in the second module. Lastly, we simultaneously forced MAP and PP with other variables in the fourth multivariate analysis. Age, DM and PP remained significantly correlated with PWV, but the significance of MAP was lost. This is the first invasive study to suggest that PP has the strongest correlation with PWV among a variety of BP parameters.

Delayed severe multivessel spasm and aborted sudden death after Taxus stent implantation

Sudden cardiac arrest associated with major spasm of three coronary arteries was observed about 10 hours after Taxus stent insertion in a three vessel lesion and was successfully treated by intracoronary glyceryl trinitrate infusion. This case illustrates a potential risk associated with drug eluting stent and alerts clinicians to the life threatening risk of spasm when stenting multiple vessels with drug eluting stent (especially the Taxus stent).

Inflammation, insulin resistance, and glucose intolerance in acute myocardial infarction patients without a previous diagnosis of diabetes mellitus

We examined the prevalence of impaired glucose metabolism and its association with inflammation and insulin resistance (IR) in acute myocardial infarction (AMI) patients without a previous diagnosis of diabetes. This prospective study enrolled 52 AMI patients, and 75-g oral glucose tolerance testing was performed on 30 patients at discharge and again 3 months later. We also measured serum adiponectin, high sensitive C-reactive protein, and IL-6 on both occasions. Data were compared with those of 30 type 2 diabetic patients without a history of AMI. Forty percent and 36.7% of AMI patients had impaired glucose tolerance (IGT) at discharge and at 3 months, respectively. The corresponding proportions for newly diagnosed diabetes are 33.0% and 30.0%. At discharge, AMI patients with IGT or diabetes showed higher high sensitive C-reactive protein and IL-6 levels compared with AMI patients with normal glucose tolerance or control type 2 diabetic patients. Furthermore, AMI patients with IGT or diabetes exhibited higher IR and lower serum adiponectin levels than AMI patients with normal glucose tolerance at 3 months after discharge. Previously undiagnosed diabetes and IGT are common in Korean patients with AMI. These glycometabolic abnormalities are associated with inflammation, IR, and serum adiponectin levels.

Dexamethasone suppresses the expansion and transdifferentiation of transplanted porcine neonatal pancreas cell clusters (NPCCs) into beta-cells in normal nude mice

OBJECTIVES

This study was performed to investigate the effect of dexamethasone on the expansion and transdifferentiation of transplanted neonatal pancreas cell clusters (NPCCs) in vivo.

METHODS

Porcine NPCCs were generated from 1 to 3-day-old neonatal pigs. After transplantation (Tx) of 4000 islet equivalents (IEqs) of NPCCs beneath the renal subcapsular space of normoglycemic nude mice, dexamethasone (Dx, 1 mg/kg) or vehicles were injected daily. Intraperitoneal glucose tolerance testing (ip-GTT) was performed at 4 weeks (n = 4) and 10 weeks (n = 7) after Tx. After harvesting the grafts, total graft and beta-cell graft mass were determined by morphometric analysis.

RESULTS

Although the mean value of AUCg was elevated in the Dx-treated group at 10 weeks after Tx, the glucose levels of all the animals by ip-GTT were within the normal range. At 10 weeks after Tx, the relative volume, absolute mass of beta-cells in the graft, and total graft mass were significantly lower in the Dx-treated group (relative volume of beta-cells: 22.0% versus 35.3%, P < 0.05; beta-cells mass: 1.0 +/- 1.2 mg versus 2.2 +/- 5.6 mg, P < 0.05, total graft mass: 4.4 +/- 5.4 mg versus 6.3 +/- 1.3 mg, P < 0.05, Dx-treated versus control), but there was no difference at 4 weeks. Morphologically prominent cystic structures were observed in the Dx group at 10 weeks.

CONCLUSION

Our results suggest that dexamethasone suppresses the expansion and transdifferentiation of transplanted porcine NPCCs into beta-cells in normal nude mice.