Lactobacillus acidophilus KBL409 protects against kidney injury via improving mitochondrial function with chronic kidney disease

PURPOSE

Recent advances have led to greater recognition of the role of mitochondrial dysfunction in the pathogenesis of chronic kidney disease (CKD). There has been evidence that CKD is also associated with dysbiosis. Here, we aimed to evaluate whether probiotic supplements can have protective effects against kidney injury via improving mitochondrial function.

METHODS

An animal model of CKD was induced by feeding C57BL/6 mice a diet containing 0.2% adenine. KBL409, a strain of Lactobacillus acidophilus, was administered via oral gavage at a dose of 1 × 109 CFU daily. To clarify the underlying mechanisms by which probiotics exert protective effects on mitochondria in CKD, primary mouse tubular epithelial cells stimulated with TGF-β and p-cresyl sulfate were administered with butyrate.

RESULTS

In CKD mice, PGC-1α and AMPK, key mitochondrial energy metabolism regulators, were down-regulated. In addition, mitochondrial dynamics shifted toward fission, the number of fragmented cristae increased, and mitochondrial mass decreased. These alterations were restored by KBL409 administration. KBL409 supplementation also improved defects in fatty acid oxidation and glycolysis and restored the suppressed enzyme levels involved in TCA cycle. Accordingly, there was a concomitant improvement in mitochondrial respiration and ATP production assessed by mitochondrial function assay. These favorable effects of KBL409 on mitochondria ultimately decreased kidney fibrosis in CKD mice. In vitro analyses with butyrate recapitulated the findings of animal study.

CONCLUSIONS

This study demonstrates that administration of the probiotic Lactobacillus acidophilus KBL409 protects against kidney injury via improving mitochondrial function.

Intra-abdominal desmoid fibromatosis mimicking tumour recurrence after the operation: A case series

INTRODUCTION

Desmoid fibromatosis is a multifactorial disorder classified as a category of intermediate, locally aggressive behaviour, which might be associated with CTNNB1 or APC mutations, trauma, surgery, or pregnancy.

CASE REPORTS

We present two cases of postoperative intra-abdominal desmoid fibromatosis. The first case occurred 14 months after the resection of a retroperitoneal gastrointestinal stromal tumour. The second case was located in the mesentery, as evidenced on an 18-month followup after a laparoscopy-assisted anterior resection for adenocarcinoma at the rectosigmoid junction. Under the clinical diagnosis of recurrence, tissue excisions were conducted. Microscopically, the tissue was composed of bland spindle cells without cytological atypia, admixed with collagen bundles. Both tumours exhibited nuclear expression of β-catenin on immunohistochemical staining, which is a desirable criterion for desmoid fibromatosis.

DISCUSSION

Although positron emission tomography aids the diagnosis of recurrence, the radiological features of desmoid fibromatosis in computed tomography or magnetic resonance images are nonspecific and preoperative diagnosis of desmoid fibromatosis is difficult. The histological diagnosis of desmoid fibromatosis is difficult, especially when the specimen is small. The histological differential diagnosis of desmoid fibromatosis includes other myofibroblastic or fibroblastic tumours or lesions. Additional studies, such as β-catenin immunohistochemistry or CTNNB1 mutation analysis, can enable accurate diagnosis of desmoid fibromatosis. A correct diagnosis is essential, because the current therapeutic strategy is a "waitand- watch" approach, which is significantly different from those of the other locally aggressive, intermediate soft tissue neoplasms. We have summarised the clinicopathological, histological and immunohistochemical features of the post-operative desmoid fibromatosis.

Low-density lipoprotein cholesterol levels and adverse clinical outcomes in chronic kidney disease: Results from the KNOW-CKD

BACKGROUND AND AIMS

The optimal low-density lipoprotein cholesterol (LDL-C) level to prevent cardiovascular disease in chronic kidney disease (CKD) patients remains unknown. This study aimed to explore the association of LDL-C levels with adverse cardiovascular and kidney outcomes in Korean CKD patients and determine the validity of "the lower, the better" strategy for statin intake.

METHODS AND RESULTS

A total of 1886 patients from the KoreaN cohort study for Outcome in patients With CKD (KNOW-CKD) were included. Patients were classified into four LDL-C categories: <70, 70-99, 100-129, and ≥130 mg/dL. The primary outcome was extended major adverse cardiovascular events (eMACEs). Secondary outcomes included all-cause mortality, and CKD progression. During the follow-up period, the primary outcome events occurred in 136 (7.2%) patients (16.9 per 1000 person-years). There was a graded association between LDL-C and the risk of eMACEs. The hazard ratios (95% confidence intervals) for LDL-C categories of 70-99, 100-129, and ≥130 mg/dL were 2.06 (1.14-3.73), 2.79 (1.18-6.58), and 4.10 (1.17-14.3), respectively, compared to LDL-C <70 mg/dL. Time-varying analysis showed consistent findings. The predictive performance of LDL-C for eMACEs was affected by kidney function. Higher LDL-C levels were also associated with significantly higher risks of CKD progression. However, LDL-C level was not associated with all-cause mortality.

CONCLUSIONS

This study showed a graded relationship between LDL-C and the risk of adverse cardiovascular outcome in CKD patients. The lowest risk was observed with LDL-C <70 mg/dL, suggesting that a lower LDL-C target may be acceptable.

Body weight fluctuation is associated with rapid kidney function decline

OBJECTIVE

This study aimed to evaluate the effects of body weight fluctuations on kidney function deterioration in a prospective cohort of individuals with normal kidney function.

METHODS

Data were obtained from the Korean Genome and Epidemiology Study. Body weight fluctuations were determined using average successive variability (ASV), which was defined as the average absolute body weight change using repeated measurements for all participants. The decline of the estimated glomerular filtration rate (eGFR) over time was calculated using linear regression analysis of serial eGFR measurements for each patient. Rapid eGFR decline was defined as an average eGFR decline > 3 mL/min/1.73 m² per year.

RESULTS

A total of 6,790 participants were analyzed. During a median follow-up of 11.7 years, rapid eGFR decline was observed in 913 (13.4%) participants. When the participants were categorized into tertiles according to ASV, rapid eGFR decline was more prevalent in the highest ASV tertile group than in the lowest. Analyses using multiple logistic regression models revealed that the risk of rapid eGFR decline was increased in the highest ASV tertile group compared with the lowest (odds ratio: 1.66).

CONCLUSIONS

Body weight fluctuations were significantly associated with an increased risk of rapid kidney function decline in participants with normal kidney function.

Increased Risk of Chronic Kidney Disease Associated With Weight Gain in Healthy Adults: Insight From Metabolic Profiles and Body Composition

Objective: Obesity is an established risk factor for kidney damage. In this study, we explored the long-term association of changes in body mass index (BMI) over time with incident chronic kidney disease (CKD).

Methods: For this analysis, 5,393 middle-aged adults without comorbidities in the Korean Genome and Epidemiology Study (KoGES) were included. Group-based trajectory modeling was used to determine the patterns of BMI change (decreasing, stable, and increasing BMI) between baseline and year 4. The primary outcome was the subsequent development of CKD from year 4. A multivariable Cox proportional hazards model was constructed to determine the risk of incident CKD according to BMI trajectories.

Results: During 55,327 person-years, incident CKD occurred in 354 (6.5%) participants; 6.0, 6.1, and 7.8 per 1,000 person-years across the trajectories, respectively (P = 0.005). In the multivariable-adjusted Cox proportional hazards model, the increasing BMI trajectory was associated with a 1.4-fold [hazard ratio (HR), 1.41; 95% CI, 1.06–1.87] a higher risk of incident CKD compared with stable BMI trajectory. This association was stronger for overweight and obese individuals. The HRs for CKD development in these two groups were 1.6 (95% CI, 1.06–1.87) and 2.2 (95% CI, 1.40–3.48), respectively. While the increasing BMI group was gaining weight, there were concomitant increases in blood pressure, insulin resistance, serum concentrations of total cholesterol, triglyceride, and high-sensitivity C-reactive protein (hs-CRP), and fat mass, but high-density lipoprotein (HDL)-cholesterol level and muscle-to-fat (MF) ratio decreased.

Conclusion: Weight gain is associated with an increased risk of incident CKD in healthy adults. This association is attributed to worsening metabolic profiles and increasing fat mass.

Association Between Longitudinal Blood Pressure Trajectory and the Progression of Chronic Kidney Disease: Results From the KNOW-CKD

Studies on the longitudinal temporal trend of blood pressure (BP) and its impact on kidney function are scarce. Here, we evaluated the association of dynamic changes in systolic blood pressure (SBP) over time with adverse kidney outcomes. We analyzed 1837 participants from the KNOW-CKD (Korean Cohort Study for Outcomes in Patients With Chronic Kidney Disease). The main exposure was 3 distinct SBP trajectories determined by the latent class mixed model (decreasing, stable, and increasing) using 3 SBP measurements at 0, 6, and 12 months. The primary outcome was CKD progression, defined as a composite of halving estimated glomerular filtration rate from baseline value or onset of end-stage kidney disease. SBP declined from 144 to 120 mm Hg in the decreasing SBP trajectory group and rose from 114 to 136 mm Hg in the increasing trajectory group within 1 year. During 6576 person-years of follow-up (median, 3.7 years), the composite outcome occurred in 521 (28.4%) participants. There were fewer primary outcome events in the decreasing (30.6%) and stable (26.5%) SBP trajectory groups than in the increasing trajectory group (33.0%). In the multivariable-adjusted cause-specific hazards model, increasing SBP trajectory was associated with a 1.28-fold higher risk for adverse kidney outcome compared with stable SBP trajectory. However, the risk for the primary outcome did not differ between the decreasing and stable SBP trajectory groups. In this longitudinal CKD cohort study, compared with stable SBP trajectory, increasing SBP trajectory was associated with higher risk for adverse kidney outcome, whereas decreasing SBP trajectory showed similar risk.

Smoking, Smoking Cessation, and Progression of Chronic Kidney Disease: Results From KNOW-CKD Study

INTRODUCTION

In patients with chronic kidney disease (CKD), studies investigating the association between smoking and deterioration of kidney function are scarce.

AIMS AND METHODS

We analyzed data for 1,951 patients with an estimated glomerular filtration rate (eGFR) ≥15 mL/min/1.73 m2 enrolled in the KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD) from 2011 to 2016. Patients were categorized by smoking load. Primary outcome was a composite of a ≥50% reduction in eGFR, initiation of dialysis, or kidney transplantation.

RESULTS

There were 967 never-smokers and 369, 276, and 339 smokers who smoked <15, 15 to 29, ≥30 pack-years, respectively. During a mean follow-up of 3.0 years, the incidence rates (95% confidence interval [CI]) of the primary outcome were 54.3 (46.4-63.5), 46.9 (35.9-61.4), 69.2 (52.9-90.6), and 76.3 (60.7-96.0) events per 1,000 person-yr in never-, <15, 15 to 29, and ≥30 pack-year smokers. In cause-specific hazard model after adjustment of confounding factors, smokers were associated with 1.09 (0.73-1.63), 1.48 (1.00-2.18), and 1.94 (1.35-2.77) fold increased risk (95% CI) of primary outcome in <15, 15-29, and ≥30 pack-year smokers compared with never-smokers. The association of longer smoking duration with higher risk of CKD progression was evident particularly in patients with eGFR < 45 mL/min/1.73 m2 and proteinuria ≥ 1.0 g/g. In contrast, the risk of adverse kidney outcome decreased with longer smoking-free periods among former-smokers.

CONCLUSIONS

These findings suggest potentially harmful effects of the degree of exposure to smoking on the progression of CKD.

IMPLICATIONS

Among patients with CKD, there has been lack of studies on the association between smoking and CKD progression and studies to date have yielded conflicting results. In this prospective cohort study involving Korean CKD patients, smoking was associated with significantly higher risk of worsening kidney function. Furthermore, the risk of adverse kidney outcome was incrementally higher as smoking pack-years were higher. As the duration of smoking cessation increased, the hazard ratios for adverse kidney outcome were attenuated, suggesting that quitting smoking may be a modifiable factor to delay CKD progression.

Association of Reproductive Lifespan Duration and Chronic Kidney Disease in Postmenopausal Women

OBJECTIVE

To investigate the relationship between endogenous estrogen exposure and renal function, the association of female reproductive life span duration (RLD) and chronic kidney disease (CKD) was analyzed in postmenopausal women.

PATIENTS AND METHODS

Data were retrieved from the Korean Genome and Epidemiology Study, which was constructed from May 1, 2001, through December 25, 2017. A total of 50,338 and 3155 postmenopausal women were each included in the cross-sectional and longitudinal analyses. The RLD was determined by subtracting the age at menarche from the age at menopause. Participants were grouped into RLD quartiles. Participants with estimated glomerular filtration rates less than 60 mL/min/1.73 m² were regarded to have CKD.

RESULTS

In the cross-sectional analysis, mean ± SD age and estimated glomerular filtration rate were 56.3±4.9 years and 93.1±13.6 mL/min/1.73 m², respectively. Mean ± SD RLD was 34.2±4.0 years. A total of 765 of 50,338 (1.52%) women were found to have CKD. Logistic regression analysis revealed that the odds ratio for CKD was lower in groups with longer RLDs as compared with the shortest RLD group. In longitudinal analysis, postmenopausal women with normal kidney function were followed up for 9.7 years and incident CKD occurred in 221 of 3155 (7.00%) participants. Cox analysis revealed that the risk for CKD development was significantly lower in longer RLD groups. This finding was significant even after adjustments for confounding factors.

CONCLUSION

The risk for CKD was lower in women with longer RLDs. The amount of endogenous estrogen exposure could be a determining factor for renal function in postmenopausal women.

Low High-Sensitivity C-Reactive Protein Level in Korean Patients With Chronic Kidney Disease and Its Predictive Significance for Cardiovascular Events, Mortality, and Adverse Kidney Outcomes: Results From KNOW-CKD

Background Inflammation levels are lower in East Asians than in Western people. We studied the association between high-sensitivity hs-CRP (C-reactive protein) and adverse outcomes in Korean patients with chronic kidney disease. Methods and Results We included 2018 participants from the KNOW-CKD (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease) between April 2011 and February 2016. The primary outcome was a composite of extended major cardiovascular events (eMACE) or all-cause mortality. The secondary end points were separate outcomes of eMACE, all-cause death, and adverse kidney outcome. We also evaluated predictive ability of hs-CRP for the primary outcome. The median hs-CRP level was 0.60 mg/L. During the mean follow-up of 3.9 years, there were 125 (6.2%) eMACEs and 80 (4.0%) deaths. In multivariable Cox analysis after adjustment of confounders, there was a graded association of hs-CRP with the primary outcome. The hazard ratios for hs-CRPs of 1.0 to 2.99 and ≥3.0 mg/L were 1.33 (95% CI, 0.87-2.03) and 2.08 (95% CI, 1.30-3.33) compared with the hs-CRP of <1.0 mg/L. In secondary outcomes, this association was consistent for eMACE and all-cause death; however, hs-CRP was not associated with adverse kidney outcomes. Finally, prediction models failed to show improvement of predictive performance of hs-CRP compared with conventional factors. Conclusions In Korean patients with chronic kidney disease, the hs-CRP level was low and significantly associated with higher risks of eMACEs and mortality. However, hs-CRP did not associate with adverse kidney outcome, and the predictive performance of hs-CRP was not strong. Registration URL: http://www.clinicaltrials.gov; Unique identifier: NCT01630486.

The effect of interactions between proteinuria, activity of fibroblast growth factor 23 and serum phosphate on renal progression in patients with chronic kidney disease: a result from the KoreaN cohort study for Outcome in patients With Chronic Kidney Disease study

BACKGROUND

Recent experimental study reported that proteinuria increases serum phosphate by decreasing biologic activity of fibroblast growth factor 23 (FGF-23). We examined this relationship in a large chronic kidney disease (CKD) cohort and evaluated the combined effect of proteinuria, FGF-23 activity and serum phosphate on CKD progression.

METHODS

The activity of FGF-23, measured by the fractional excretion of phosphate (FEP)/FGF-23 ratio, was compared according to the degree of proteinuria in 1909 patients with CKD. Primary outcome was CKD progression defined as ≥50% decline of estimated glomerular filtration rate, doubling of serum creatinine and start of dialysis.

RESULTS

There was a negative relationship between 24-h urine protein (24-h UP) and FEP/FGF-23 ratio (γ -0.07; P = 0.005). In addition, after matching variables associated with serum phosphate, patients with more proteinuria had higher serum phosphate (P < 0.001) and FGF-23 (P = 0.012), and lower FEP/FGF-23 ratio (P = 0.007) compared with those with less proteinuria. In the matched cohort, low FEP/FGF-23 ratio was an independent risk factor for CKD progression (hazard ratio 0.87 per 1 log increase; 95% confidence interval 0.79-0.95; P = 0.002), and there was significant interaction between 24-h UP and FEP/FGF-23 ratio (P = 0.039). Furthermore, 24-h UP and serum phosphate also had a significant interaction on CKD progression (P < 0.001).

CONCLUSIONS

Proteinuria is associated with decreased biologic activity of FGF-23 and increased serum phosphate. Furthermore, diminished activity of FGF23 is an independent risk factor for renal progression in proteinuric CKD patients.

Association of smoking with incident CKD risk in the general population: A community-based cohort study

BACKGROUND

Chronic kidney disease (CKD) is a public health problem, and an unfavorable lifestyle has been suggested as a modifiable risk factor for CKD. Cigarette smoking is closely associated with cardiovascular disease and cancers; however, there is a lack of evidence to prove that smoking is harmful for kidney health. Therefore, we aimed to determine the relationship between cigarette smoking and CKD among healthy middle-aged adults.

METHODS

Using the database from the Korean Genome and Epidemiology Study, we analyzed 8,661 participants after excluding those with baseline estimated glomerular filtration rate (eGFR)<60 ml/min/1.72 m2 or proteinuria. Exposure of interest was smoking status: never-, former-, and current-smokers. Primary outcome was incident CKD defined as eGFR <60 ml/min/1.73 m2 or newly developed proteinuria.

RESULTS

The mean age of the subjects was 52 years, and 47.6% of them were males. There were 551 (6.4%) and 1,255 (14.5%) subjects with diabetes and hypertension, respectively. The mean eGFR was 93.0 ml/min/1.73 m2. Among the participants, 5,140 (59.3%), 1,336 (15.4%), and 2,185 (25.2%) were never-smokers, former-smokers, and current-smokers, respectively. During a median follow-up of 11.6 years, incident CKD developed in 1,941 (22.4%) subjects with a crude incidence rate of 25.1 (24.0-26.2) per 1,000 person-years. The multivariable Cox regression analysis after adjustment of confounding factors showed hazard ratios (95% confidence interval) of 1.13 (0.95-1.35) and 1.26 (1.07-1.48) for CKD development in the former- and current-smokers, compared with never-smokers.

CONCLUSION

This study showed that smoking was associated with a higher risk of incident CKD among healthy middle-aged adults.

Association Between Serum High-Density Lipoprotein Cholesterol Levels and Progression of Chronic Kidney Disease: Results From the KNOW-CKD

Background High-density lipoprotein cholesterol ( HDL -C) levels are generally decreased in patients with chronic kidney disease ( CKD ). However, studies on the relationship between HDL -C and CKD progression are scarce. Methods and Results We studied the association between serum HDL -C levels and the risk of CKD progression in 2168 participants of the KNOW - CKD (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease). The primary outcome was the composite of a 50% decline in estimated glomerular filtration rate from baseline or end-stage renal disease. The secondary outcome was the onset of end-stage renal disease. During a median follow-up of 3.1 (interquartile range, 1.6-4.5) years, the primary outcome occurred in 335 patients (15.5%). In a fully adjusted Cox model, the lowest category with HDL -C of <30 mg/dL (hazard ratio, 2.21; 95% CI, 1.30-3.77) and the highest category with HDL -C of ≥60 mg/dL (hazard ratio, 2.05; 95% CI , 1.35-3.10) were associated with a significantly higher risk of the composite renal outcome, compared with the reference category with HDL -C of 50 to 59 mg/dL. This association remained unaltered in a time-varying Cox analysis. In addition, a fully adjusted cubic spline model with HDL -C being treated as a continuous variable yielded similar results. Furthermore, consistent findings were obtained in a secondary outcome analysis for the development of end-stage renal disease. Conclusions A U-shaped association was observed between serum HDL -C levels and adverse renal outcomes in this large cohort of patients with CKD . Our findings suggest that both low and high serum HDL -C levels may be detrimental to patients with nondialysis CKD .

Dietary zinc intake and incident chronic kidney disease

BACKGROUND & AIMS

Previous studies have shown that dietary zinc intake is closely related to cardiovascular complications and metabolic derangements. However, the effect of dietary zinc intake on renal function is not fully elucidated.

METHODS

Data from the Korean Genome and Epidemiology Study were used. Dietary zinc intake was assessed by a Food Frequency Questionnaire and dietary zinc density was calculated as absolute zinc intake amount per daily energy intake (mg/1000 kcal day). The participants were categorized into quartiles according to dietary zinc density. The primary end point was incident chronic kidney disease (CKD), defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m².

RESULTS

A total of 7735 participants with normal renal function was included in the final analysis. The mean age was 52.0 ± 8.8 years, 47.5% were male, and mean eGFR was 92.1 ± 16.1 ml/min/1.73 m². The mean daily zinc intake and zinc intake density were 8.6 ± 3.4 mg and 4.4 ± 0.9 mg/1000 kcal, respectively. During a median follow up of 11.5 (1.7-12.5) years and 70,617 person-years of observation, CKD developed in 1409 (18.2%) participants. Multivariable cox hazard analysis revealed that risk for CKD development was significantly higher in the quartile with a mean zinc intake density of 3.6 ± 0.2 mg/1000 kcal compared with the quartile with a mean zinc intake density of 5.6 ± 1.0 mg/1000 kcal (Hazard ratio; 1.36; 95% Confidence Interval 1.18-1.58; P < 0.001). This relationship remained significant even after adjustments for confounding factors.

CONCLUSION

Low dietary zinc intake may increase the risk of CKD development in individuals with normal renal function.

P0926ASSOCIATION OF HIGH-SENSITIVE C-REACTIVE PROTEIN WITH CARDIOVASCULAR EVENTS, MORTALITY, AND ADVERSE KIDNEY OUTCOMES IN KOREAN PATIENTS WITH CHRONIC KIDNEY DISEASE: RESULTS FROM KNOW-CKD

Background and Aims

High-sensitivity C-reactive protein (hs-CRP) level is lower in East Asians than in the Western people and its clinical significance needs to be further explored. We aimed to investigate whether hs-CRP could function as a biomarker in Korean CKD patients.

Method

We studied the association of hs-CRP with adverse clinical outcomes in 2,018 patients from the KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD). The primary outcome was a composite of extended major cardiovascular events (MACE) or all-cause mortality. Extended MACE (eMACE) included non-fatal cardiovascular events, symptomatic arrhythmia, and cardiac death. The secondary endpoints were separate outcome of eMACE, all-cause death, and adverse kidney outcome. We also evaluated predictive ability of hs-CRP for the primary outcome.

Results

The median hs-CRP level was 0.60 mg/L (IQR 0.2-1.7), and the mean eGFR was 53.6 ml/min/1.73 m2. During the mean follow-up of 3.9 years, there were 125 (6.2%) eMACEs and 80 (4.0%) deaths. The primary composite outcome occurred more frequently in patients with higher hs-CRP level than in those with lower hs-CRP level. In multivariable Cox analysis after adjustment of confounders, there was a graded association of hs-CRP with the primary outcome. The HRs (95% CI) for hs-CRP of 1.0 to 2.99, and ≥ 3.0 mg/L were 1.37 (0.89-2.12) and 2.20 (1.36-3.56), compared with

hs-CRP of &lt;1.0 mg/L. In analyses of secondary outcomes, this association was consistent for eMACE and all-cause death; however, hs-CRP was not associated with adverse kidney outcomes. Finally, prediction models failed to show improvement of predictive performance of hs-CRP compared to conventional factors.

Conclusion

In Korean CKD patients, serum hs-CRP level was low and significantly associated with higher risk of eMACEs and mortality. However, a low serum hs-CRP level was not predictive of adverse kidney outcome, and the predictive performance of hs-CRP was not strong.

Alcohol Consumption and Progression of Chronic Kidney Disease: Results From the Korean Cohort Study for Outcome in Patients with Chronic Kidney Disease

OBJECTIVE

To assess the association of alcohol consumption with chronic kidney disease (CKD) progression in patients with CKD.

PATIENTS AND METHODS

The KoreaN cohort study for Outcome in patients with CKD (KNOW-CKD) is a prospective observational study that included detailed questionnaires regarding alcohol consumption. The 1883 individuals with CKD were enrolled from April 1, 2011, through February 28, 2016, and followed until May 31, 2017. Using a questionnaire, alcohol consumption pattern was classified according to the amount of alcohol per occasion (none, moderate, or binge) or drinking frequency (none, occasional, or regular). The primary endpoint was a composite of 50% or greater decline in estimated glomerular filtration rate (eGFR) from the baseline level or end-stage renal disease.

RESULTS

During a follow-up of 5555 person-years (median, 2.95 years), the primary outcome occurred in 419 patients. Unadjusted cause-specific hazards model showed that the risk of the primary outcome was lower in drinkers than in non-drinkers. However, a fully adjusted model including eGFR and proteinuria yielded a reverse association. Compared with non-drinking, regular and occasional binge drinking were associated with a 2.2-fold (95% CI, 1.38-3.46) and a 2.0-fold (95% CI, 1.33-2.98) higher risk of CKD progression, respectively. This association was particularly evident in patients who had decreased kidney function and proteinuria. There was a significant interaction between alcohol consumption and eGFR for CKD progression. The slopes of eGFR decline were steeper in binge drinkers among patients with eGFR less than 60 mL/min/1.73 m².

CONCLUSIONS

Heavy alcohol consumption was associated with faster progression of CKD.

Snoring and incident chronic kidney disease: a community-based prospective cohort study

OBJECTIVES

Previous studies have shown that symptoms of sleep-disordered breathing are associated with metabolic derangements and vascular disease development. However, the relationship between snoring and renal function is not well investigated. The association between snoring and the development of incident chronic kidney disease (CKD) in subjects with normal renal function was evaluated.

DESIGN

Prospective cohort study.

SETTING

Ansung (rural community) and Ansan (urban community) cities.

PARTICIPANTS

Community-based cohort participants aged 40-69 years.

METHODS

A total of 9062 participants in the Ansung-Ansan cohort study were prospectively followed up from 2001 to 2014. The participants were classified into three groups: non-snorer, <1 day/week and ≥1 day/week. The main outcome was incident CKD, which was defined as an estimated glomerular filtration rate of <60 mL/min/1.73 m² during the follow-up period.

PRIMARY OUTCOME

Incident CKD.

RESULTS

The mean subject age was 52.0±8.9 years, and 4372 (48.2%) subjects were male. The non-snorer,<1 day/week and ≥1 day/week groups included 3493 (38.5%), 3749 (41.4%), and 1820 (20.1%) subjects, respectively. Metabolic syndrome was more prevalent in the snoring groups than in the non-snoring group. Snoring frequency showed a significant positive relationship with age, waist:hip ratio, fasting glucose, total cholesterol (Tchol) and low-density lipoprotein cholesterol. During a mean follow-up of 8.9 years, 764 (8.4%) subjects developed CKD. Cox proportional hazards model analysis revealed that the risk of CKD development was significantly higher in subjects who snored ≥1 day/week than in non-snorers, even after adjustments for confounding factors (HR 1.23, 95% CI 1.09 to 1.38, p<0.01).

CONCLUSION

Snoring may increase the risk of CKD development in subjects with normal renal function.

Framingham risk score and risk of incident chronic kidney disease: A community-based prospective cohort study

Background

Cardiovascular disease and chronic kidney disease share several common risk factors. The Framingham risk score is hypothesized to predict chronic kidney disease development. We determined if the Framingham risk scoring system can correctly predict incident chronic kidney disease in the general population.

Methods

This study included 9,080 subjects who participated in the Korean Genome and Epidemiology Study between 2001 and 2014 and had normal renal function. The subjects were classified into low- (< 10%), intermediate- (10-20%), and high- (> 20%) risk groups based on baseline Framingham risk scores. The primary endpoint was de novo chronic kidney disease development (estimated glomerular filtration rate [eGFR], < 60 mL/min/1.73 m²).

Results

During a mean follow-up duration of 8.9 ± 4.3 years, 312 (5.3%), 217 (10.8%), and 205 (16.9%) subjects developed chronic kidney disease in the low, intermediate, and high risk groups, respectively (P < 0.001). Multivariable analysis after adjustment for confounding factors showed the hazard ratios for the high- and intermediate risk groups were 2.674 (95% confidence interval [CI], 2.197-3.255) and 1.734 (95% CI, 1.447-2.078), respectively. This association was consistently observed irrespective of proteinuria, age, sex, obesity, or hypertension. The predictive power of this scoring system was lower than that of renal parameters, such as eGFR and proteinuria, but increased when both were included in the prediction model.

Conclusion

The Framingham risk score predicted incident chronic kidney disease and enhanced risk stratification in conjunction with traditional renal parameters in the general population with normal renal function.

Effects of Coffee Intake on Incident Chronic Kidney Disease: A Community-Based Prospective Cohort Study

BACKGROUND

Drinking coffee can raise public health problems, but the association between coffee and kidney disease is unknown. We studied whether coffee intake can affect the development of chronic kidney disease in the general population.

METHODS

We analyzed 8717 subjects with normal renal function recruited from the Korean Genome and Epidemiology Study (KoGES) cohort. Based on a food frequency questionnaire, coffee consumption was categorized into 5 groups: 0 per week, <1 cup per week, 1-6 cups per week, 1 cup per day, and ≥2 cups per day. The primary outcome was incident chronic kidney disease, defined as an estimated glomerular filtration rate <60 mL/min/1.73 m².

RESULTS

The mean age (standard deviation) of study subjects was 52.0 (8.8) years, and 47.8% were male. Among the subjects, 52.8% were daily coffee consumers. During a mean follow-up of 11.3 (range, 5.9-11.5) years, 9.5% of participants developed chronic kidney disease. The incident chronic kidney disease occurred less in daily coffee consumers. Unadjusted hazard ratios (HRs) was significantly lower in daily coffee consumers. In multivariable Cox model even after adjustment of blood pressure, hypertension, cardiovascular disease, diabetes, and amount of daily intake for caffeine-containing foods such as tea and chocolate, coffee consumers with 1 cup per day (HR, 0.76; 95% confidence interval, 0.63-0.92) and ≥2 cups per day (HR, 0.80; 95% confidence interval, 0.65-0.98) were associated with a lower risk of chronic kidney disease development than nondrinkers. Time-averaged and time-varying Cox models yielded similar results. The rates of decline in glomerular filtration were lower in daily coffee consumers.

CONCLUSIONS

Our findings suggest that daily coffee intake is associated with decreased risk of the development of chronic kidney disease.

Changes in obese metabolic phenotypes over time and risk of incident chronic kidney disease

AIM

To examine the association between metabolically healthy obese (MHO) phenotype and incident chronic kidney disease (CKD) and study whether changes in metabolic phenotypes over time could affect CKD risk.

METHODS

A total of 8589 subjects from the Korean Genome and Epidemiology Study were categorized into four groups based on the presence of obesity and metabolic abnormalities (MA). The primary endpoint was an onset of incident CKD defined as an estimated glomerular filtration rate of ≤ 60 mL/min/1.73 m² . Multivariable Cox analysis and time-varying Cox analysis were performed to delineate the relationship between obese metabolic phenotypes and incident CKD after adjustment for sociodemographic factors and clinical and laboratory parameters.

RESULTS

During a mean follow-up duration of 9.3 years, CKD occurred in 782 (9.1%) participants. In the multivariable Cox model, the hazard ratio (HR) for incident CKD in the MHO, metabolically abnormal non-obese (MANO), and metabolically abnormal obese (MAO) groups was 1.42 (P = 0.002), 1.45 (P < 0.001), and 1.77 (P < 0.001), respectively, compared with the metabolically healthy non-obese (MHNO) group. Time-varying analysis with these four phenotypes as time-varying exposures showed the same results. Furthermore, subjects with persistent MHO through follow-up were at a 2.0-fold increased risk of CKD (P < 0.001). 41.0% of subjects experienced phenotype changes during follow-up. Over the long term, the MHO group had a higher proportion of transition to the MA phenotype and unfavourable metabolic profiles than the MHNO group. Among MHO subjects, those who transitioned to MAO were at a 4.1-fold increased risk of incident CKD than those who regressed to MHNO. In addition, transition to MHO from other groups carried a higher risk of CKD than persistent MHNO.

CONCLUSION

MHO subjects are at increased risk for incident CKD.

Severe vitamin D deficiency is a risk factor for renal hyperfiltration

Background

Vitamin D deficiency is associated with renal progression in chronic kidney disease. Moreover, improvement of clinical outcomes after vitamin D supplementation has been reported in the diabetic and chronic kidney disease population.

Objective

We investigated the association between renal hyperfiltration (RHF) and vitamin D status in a relatively healthy population.

Design

Data were retrieved from the Korean NHANES, a nationwide population-based cross-sectional study from 2008 to 2015. Overall, 33,210 subjects with normal renal function were included in the final analysis. Severe vitamin D deficiency was defined as serum 25-hydroxyvitamin D concentration <10 ng/mL. RHF was defined as estimated glomerular filtration rate with residual in the >95th percentile after adjustment for age, sex, height, weight, and history of hypertension or diabetes.

Results

The mean ± SD age of subjects was 48.1 ± 15.9 y, and the number of women was 18,779 (56.5%). Estimated glomerular filtration rate was negatively associated with serum 25-hydroxyvitamin D concentrations in multivariable linear regression analysis (β: -0.02; 95% CI: -0.02, -0.01; P < 0.001). Furthermore, 1637 (4.9%) subjects were categorized into the RHF group, and the prevalence of RHF was significantly higher in the severe vitamin D deficiency group than in the sufficiency group (5.8% compared with 5.0%, P < 0.001). In a multivariable logistic regression model, severe vitamin D deficiency was a significant risk factor for RHF (OR: 2.41; 95% CI, 1.72, 3.43; P < 0.001).

Conclusions

Severe vitamin D deficiency is significantly associated with increasing prevalence of RHF in a relatively healthy adult population.

Risk of Retinal Vein Occlusion in Patients With End-Stage Renal Disease: A 12-Year, Retrospective, Nationwide Cohort Study in South Korea

Purpose

The present study aimed to evaluate the risk of retinal vein occlusion (RVO) in Korean patients with end-stage renal disease (ESRD).

Methods

In this retrospective, nationwide, propensity score-matched cohort study, subjects were randomly enrolled from the 12-year longitudinal Korean National Health Insurance Service-National Sample Cohort 2002-2013 database comprising 1 million subjects. The ESRD group comprised 988 patients newly diagnosed with ESRD from 2003 onward by washing out data from 2002. The comparison group comprised 4940 (5 for each patient with ESRD) randomly selected propensity score-matched individuals not diagnosed with ESRD. Each sampled patient was tracked until 2013 for RVO development. Multiple conditional Cox regression analysis was performed to compare the risk of RVO between the two groups.

Results

The mean follow-up period was 7.37 years. The incidence of RVO was 3.95% in the ESRD group and 2.17% in the comparison group (P = 0.001). ESRD was associated with greater risk of RVO development after adjustment for possible confounders (adjusted hazard ratio [HR], 2.122; 95% confidence interval [CI], 1.396-3.226; P = 0.0004). The 50- to 60-year (adjusted HR, 2.635; 95% CI, 1.100-6.313; P = 0.0297) and 60- to 70-year (adjusted HR, 2.544; 95% CI, 1.059-6.110; P = 0.0368) age groups exhibited higher risk of RVO compared with the <40-year age group. Hyperlipidemia (adjusted HR, 1.670; 95% CI, 1.176-2.371; P = 0.0042) and hypertension (adjusted HR, 1.896; 95% CI, 1.165-3.086; P = 0.01) were also associated with RVO.

Conclusions

An association between ESRD and subsequent RVO development was found after adjustment for possible confounding factors.

Microscopic hematuria is a risk factor of incident chronic kidney disease in the Korean general population: a community-based prospective cohort study

BACKGROUND

Although asymptomatic microscopic hematuria (MH) is a common finding in clinical practice, its long-term outcome remains unknown.

AIM

This study evaluated the clinical implication of MH in the general population using a large-scale long-term longitudinal cohort database.

METHODS

This study included 8719 participants from the Korean Genome and Epidemiology Study between 2001 and 2014. MH was defined as ≥5 red blood cells per high-power field in random urinalysis without evidence of pyuria. The primary study outcome measure was incident chronic kidney disease (CKD), defined as estimated glomerular filtration rate <60 ml min-1⋅1.73⋅m-2.

RESULTS

During a median follow-up of 11.7 years, CKD occurred in 677 (7.8%) subjects. In Cox regression after adjustment for multiple confounders, subjects with MH had a significantly higher risk of incident CKD than those without [hazard ratio (HR) 1.45, 95% confidence interval (CI) 1.12-1.87; P = 0.005]. Isolated MH without proteinuria was also a risk factor of incident CKD (HR 1.37, 95% CI 1.04-1.79; P = 0.023) and the risk was further increased in MH with concomitant proteinuria (HR 5.41, 95% CI 2.54-11.49; P < 0.001). In propensity score matching analysis after excluding subjects with proteinuria, multi-variable stratified Cox regression analysis revealed that subjects with isolated MH had a significantly higher risk of incident CKD than those without (HR 1.83, 95% CI 1.14-2.94; P = 0.012).

CONCLUSION

The presence of MH is associated with an increased risk of incident CKD in the general population. Therefore, attentive follow-up is warranted in persons with MH for early detection of CKD.

The impact of disease severity on paradoxical association between body mass index and mortality in patients with acute kidney injury undergoing continuous renal replacement therapy

BACKGROUND

Association between high body mass index (BMI) and survival benefit is confounded by comorbid conditions such as nutritional status and inflammation. Patients with acute kidney injury (AKI), particularly those receiving continuous renal replacement therapy (CRRT), are highly catabolic and more susceptible to loss of energy. Herein, we evaluated whether disease severity can modify the relationship between BMI and mortality.

METHODS

We conducted an observational study in 1144 patients who had undergone CRRT owing to various causes of AKI between 2010 and 2014. Patients were categorized into four groups; underweight (< 18.5 kg/m²), normal (18.5-22.99 kg/m²), overweight (23.0-24.99 kg/m²), and obesity (≥25 kg/m²) according to BMI classification by the Committee of Clinical Practice Guidelines and Korean Society for the Study of Obesity. More severe disease was defined as sepsis-related organ failure assessment (SOFA) score of ≥ a median value of 12. The study endpoint was death that occurred within 30 days after the initiation of CRRT.

RESULTS

The mean age was 63.2 years and 439 (38.4%) were females. The median BMI was 23.6 (20.9-26.2) kg/m². The obese group were younger and higher SOFA score than normal BMI group. In a multivariable Cox regression analysis, we found a significant interaction between BMI and SOFA score (P <  0.001). Furthermore, obese patients were significantly associated with a lower risk of death as compared to normal BMI group after adjusting confounding factors [hazard ratio (HR), 0.81; 95% confidence interval (CI), 0.68-0.97; P = 0.03]. This association was only evident among patients with high severity (HR, 0.61; 95% CI, 0.48-0.76, P <  0.001). In contrast, in those with low severity, survival benefit of high BMI was lost, whereas underweight was associated with an increased risk of death (HR, 1.74; 95% CI, 1.16-2.60; P = 0.007).

CONCLUSION

In this study, we found a survival benefit of high BMI in AKI patients undergoing CRRT, particularly in those with more disease severity; the effect was not observed in those with less disease severity.

Optimal proteinuria target for renoprotection in patients with IgA nephropathy

Background

Proteinuria is a target for renoprotection in kidney diseases. However, optimal level of proteinuria reduction in IgA nephropathy (IgAN) is unknown.

Methods

We conducted a retrospective observational study in 500 patients with biopsy-proven IgAN. Time-averaged proteinuria (TA-P) was calculated as the mean of every 6 month period of measurements of spot urine protein-to-creatinine ratio. The study endpoints were a 50% decline in estimated glomerular filtration rate (eGFR), onset of end-stage renal disease (ESRD), and slope of eGFR.

Results

During a median follow-up duration of 65 (12–154) months, a 50% decline in eGFR occurred in 1 (0.8%) patient with TA-P of <0.3 g/g compared to 6 (2.7%) patients with TA-P of 0.3–0.99 g/g (hazard ratio, 2.82; P = 0.35). Risk of reaching a 50% decline in eGFR markedly increased in patients with TA-P of 1.0–2.99 g/g (P = 0.002) and those with TA-P≥3.0 g/g (P<0.001). ESRD did not occur in patients with TA-P<1.0 g/g compared to 26 (20.0%) and 8 (57.1%) patients with TA-P of 1.0–2.99 and ≥3.0 g/g, respectively. Kidney function of these two groups deteriorated faster than those with TA-P<1.0 g/g (P<0.001). However, patients with TA-P of 0.3–0.99 g/g had a greater decline of eGFR than patients with TA-P<0.3 g/g (−0.41±1.68 vs. −0.73±2.82 ml/min/1.73 m²/year, P = 0.03).

Conclusion

In this study, patients with TA-P<1.0 g/g show favorable outcomes. However, given the faster eGFR decline in patients with TA-P of 0.3–0.99 g/g than in patients with TA-P<0.3 g/g, the ultimate optimal goal of proteinuria reduction can be lowered in the management of IgAN.

Clinical features and outcomes of focal segmental glomerulosclerosis pathologic variants in Korean adult patients

BACKGROUND

Many studies have shown that clinical characteristics and outcomes differ depending on pathologic variants of focal segmental glomerulosclerosis (FSGS). However, these are not well defined in Asian populations.

METHODS

This retrospective study evaluated clinical features and outcomes of pathologic FSGS variants in 111 adult patients between January 2004 and December 2012. Primary outcome was the composite of doubling of baseline serum creatinine concentrations (D-SCr) or onset of end-stage renal disease (ESRD). Secondary outcome included complete (CR) or partial remission (PR).

RESULTS

There were 70 (63.1%), 20 (18.0%), 17 (15.3%), 3 (2.7%), and 1 (0.9%) patients with not-otherwise specified (NOS), tip, perihilar, cellular, and collapsing variants, respectively. At presentation, nephrotic-range proteinuria occurred more commonly in tip lesion than in other variants. The overall 5-year renal survival rate was 76.8%. During a median follow-up of 34.5 months, only 1 (5.0%) patient with a tip lesion reached the composite end point compared to 2 (11.8%) and 12 (17.1%) patients in perihilar and NOS variants, but this difference was not statistically significant in an adjusted Cox model. However, tip lesion was associated with a significantly increased probability of achieving CR (P = 0.044).

CONCLUSION

Similar to other populations, Korean adult patients with FSGS have distinct clinical features with the exception of a rare frequency of cellular and collapsing variants. Although pathologic variants were not associated with overall outcome, the tip variant exhibited favorable outcome in terms of achieving remission. Further studies are required to delineate long-term outcome and response to treatment of the pathologic variants.

Comparison of the Haas and the Oxford classifications for prediction of renal outcome in patients with IgA nephropathy

Pathologic features can provide valuable information for determining prognosis in IgA nephropathy (IgAN). However, it is uncertain whether the Oxford classification, a new classification of IgAN, can predict renal outcome better than previous ones. We conducted a retrospective cohort study in 500 patients with biopsy-proven IgAN between January 2002 and December 2010 to compare the ability of the Haas and the Oxford classifications to predict renal outcome. Primary outcome was a doubling of the baseline serum creatinine concentration (D-SCr). During a mean follow-up of 68 months, 52 (10.4%) and 35 (7.0%) developed D-SCr and end-stage renal disease, respectively. There were graded increases in the development of D-SCr in the higher Haas classes. In addition, the primary endpoint of D-SCr occurred more in patients with the Oxford M and T lesions than those without such lesions. In multivariate Cox regression analyses, the Haas class V (HR, 12.19; P=.002) and the Oxford T1 (hazard ratio [HR], 6.68; P<.001) and T2 (HR, 12.16; P<.001) lesions were independently associated with an increased risk of reaching D-SCr. Harrell's C index of each multivariate model with the Haas and the Oxford classification was 0.867 (P=.015) and 0.881 (P=.004), respectively. This was significantly higher than that of model with clinical factors only (C=0.819). However, there was no difference in C-statistics between the 2 models with the Haas and the Oxford classifications (P=.348). This study suggests that the Haas and the Oxford classifications are comparable in predicting progression of IgAN.

Effect of peritoneal dialysis modality on the 1-year rate of decline of residual renal function

PURPOSE

The effect of different peritoneal dialysis (PD) modalities on the decline in residual renal function (RRF) is unclear due to inconsistencies among studies. In particular, the effect of automated peritoneal dialysis (APD) modalities [continuous cyclic peritoneal dialysis (CCPD) and nightly intermittent peritoneal dialysis (NIPD)] on RRF has not been examined in a large cohort.

MATERIALS AND METHODS

We conducted a single-center retrospective study to investigate the association between PD modalities and decline in RRF in 142 incident PD patients [34 on CCPD, 36 on NIPD, and 72 on continuous ambulatory peritoneal dialysis (CAPD)]. RRF was measured within 2 months from PD start and at 1 year after PD initiation.

RESULTS

The RRF at 1 year after PD initiation was 1.98±2.20 mL/min/1.73 m² in CCPD patients and 3.63±3.67 mL/min/1.73 m² in NIPD patients, which were moderately lower than 4.23±3.51 mL/min/1.73 m² in CAPD patients (p=0.064). Moreover, there was no significant difference in the 1-year rate of decline of RRF between CCPD and NIPD patients, although APD patients had a faster 1-year RRF decline rate than CAPD patients (CCPD and NIPD vs. CAPD: -45.68 and -36.69 vs. 1.17%/year, p=0.045). APD was associated with a more rapid decline in RRF in patients with end-stage renal disease undergoing PD, although multivariate analysis attenuated the significance of this finding (β=-31.50; 95% CI, -63.61 to 0.62; p=0.052).

CONCLUSION

Our results suggest that CAPD might be more helpful than APD for preserving RRF during the first year of dialysis therapy, although there was no significant difference in the 1-year rate of decline of RRF between the two APD modalities.

Urine output is associated with prognosis in patients with acute kidney injury requiring continuous renal replacement therapy

PURPOSE

Although some studies have found that early initiation of continuous renal replacement therapy (CRRT) is associated with better prognosis, no consensus exists on the best timing to start CRRT. We investigated whether the timing of CRRT initiation was relevant to overall mortality and explored which factors at the time of CRRT initiation were associated with better outcomes in critically ill patients with acute kidney injury (AKI).

MATERIALS AND METHODS

A total of 361 patients who received CRRT for AKI between 2009 and 2011 were collected and divided into 2 groups based on the median blood urea nitrogen (BUN) levels or 6-hour urine output immediately before CRRT was started. The impact of the timing of CRRT initiation stratified by BUN concentration or urine output on 28-day all-cause mortality was compared between groups.

RESULTS

When the timing of CRRT initiation was stratified by 6-hour urine output, 28-day all-cause mortality rates were significantly lower in the nonoliguric group compared with the oliguric group (P = .02). In contrast, clinical outcomes were not different between the low-BUN and the high-BUN groups (P = .30). Cox regression analysis revealed that 28-day all-cause mortality risk was significantly lower in the nonoliguric group stratified by 6-hour urine output, even after adjusting for age, sex, mean arterial pressure, Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores, and serum biomarkers (hazard ratio, 0.85; 95% confidence interval, 0.65-0.99; P = .04).

CONCLUSIONS

Urine output but not BUN concentration was significantly associated with a better prognosis in critically ill patients with AKI requiring CRRT.

Laser-driven proton acceleration enhancement by nanostructured foils

Nanostructured thin plastic foils have been used to enhance the mechanism of laser-driven proton beam acceleration. In particular, the presence of a monolayer of polystyrene nanospheres on the target front side has drastically enhanced the absorption of the incident 100 TW laser beam, leading to a consequent increase in the maximum proton energy and beam charge. The cutoff energy increased by about 60% for the optimal spheres' diameter of 535 nm in comparison to the planar foil. The total number of protons with energies higher than 1 MeV was increased approximately 5 times. To our knowledge this is the first experimental demonstration of such advanced target geometry. Experimental results are interpreted and discussed by means of 2(1/2)-dimensional particle-in-cell simulations.

Absolute energy calibration for relativistic electron beams with pointing instability from a laser-plasma accelerator

The pointing instability of energetic electron beams generated from a laser-driven accelerator can cause a serious error in measuring the electron spectrum with a magnetic spectrometer. In order to determine a correct electron spectrum, the pointing angle of an electron beam incident on the spectrometer should be exactly defined. Here, we present a method for absolutely calibrating the electron spectrum by monitoring the pointing angle using a scintillating screen installed in front of a permanent dipole magnet. The ambiguous electron energy due to the pointing instability is corrected by the numerical and analytical calculations based on the relativistic equation of electron motion. It is also possible to estimate the energy spread of the electron beam and determine the energy resolution of the spectrometer using the beam divergence angle that is simultaneously measured on the screen. The calibration method with direct measurement of the spatial profile of an incident electron beam has a simple experimental layout and presents the full range of spatial and spectral information of the electron beams with energies of multi-hundred MeV level, despite the limited energy resolution of the simple electron spectrometer.

P2-16-15: Oncological Safety and Survival Rate According to Reconstructive Surgery in Advanced Breast Cancer after Neoadjuvant Chemotherapy

Purpose: Oncoplastic surgery has received attention according as the incidence of breast cancer is rising and quality of life including cosmetic result after surgery is regarded as important. The aim of this study is to compare combined reconstructive surgery with standard surgery regarding to oncological safety and survival rate in advanced breast cancer after neoadjuvant chemotherapy (CTx).

Method: Thirty-seven patients underwent neoadjuvant CTx and surgery with advanced breast cancer were analyzed from September 2007 to March 2010. Group A (n=12) received combined reconstructive surgery, group B (n=25) had standard surgery.

Results: There were no differences in age, size, metastatic LN, stage, ER/PR/Her-2 status, recurrence, metastasis and death between group A and B. Patients with good response in neoadjuvant chemotherapy (26 cases (72.9%)) had CTx-operation-radiation therapy (RTx), cases with poor response (10 cases (27.1%)) underwent CTx-RTx-operation. There was significant difference in order of treatment, eight patients among group A(66.6%) had CTx-RTx-operation, 22 cases in group B(88.0%) received CTx-operation-RTx (p=0.006). Mean follow up period was 22 months, 2 patients (5.2%) experienced local recurrences, 11 cases (34.3%) diagnosed with distant metastasis, and 4 patients (10.5%) expired with breast cancer.

Novel dentin phosphoprotein frameshift mutations in dentinogenesis imperfecta type II

The dentin sialophosphoprotein (DSPP) gene encodes the most abundant non-collagenous protein in tooth dentin and DSPP protein is cleaved into several segments including the highly phosphorylated dentin phosphoprotein (DPP). Mutations in the DSPP gene have been solely related to non-syndromic form of hereditary dentin defects. We recruited three Korean families with dentinogenesis imperfecta (DGI) type II and sequenced the exons and exon-intron boundaries of the DSPP gene based on the candidate gene approach. Direct sequencing of PCR products and allele-specific cloning of the highly repetitive exon 5 revealed novel single base pair (bp) deletional mutations (c.2688delT and c.3560delG) introducing hydrophobic amino acids in the hydrophilic repeat domain of the DPP coding region. All affected members of the three families showed exceptionally rapid pulp chambers obliteration, even before tooth eruption. Individuals with the c.3560delG mutation showed only mild, yellowish tooth discoloration, in contrast to the affected individuals from two families with c.2688delT mutation. We believe that these results will help us to understand the molecular pathogenesis of DGI type II as well as the normal process of dentin biomineralization.

Novel WDR72 mutation and cytoplasmic localization

The proven candidate genes for amelogenesis imperfecta (AI) are AMELX, ENAM, MMP20, KLK4, FAM83H, and WDR72. We performed mutation analyses on seven families with hypomaturation AI. A novel WDR72 dinucleotide deletion mutation (g.57,426_57,427delAT; c.1467_ 1468delAT; p.V491fsX497) was identified in both alleles of probands from Mexico and Turkey. Haplotype analyses showed that the mutations arose independently in the two families. The disease perfectly segregated with the genotype. Only persons with both copies of the mutant allele were affected. Their hypomineralized enamel suffered attrition and orange-brown staining following eruption. Expression of WDR72 fused to green fluorescent protein showed a cytoplasmic localization exclusively and was absent from the nucleus. We conclude that WDR72 is a cytoplasmic protein that is critical for dental enamel formation.

Incidence and clinical behavior of papillary thyroid carcinoma in renal allograft recipients: a single center experience

The chronic use of immunosuppressive therapy in transplant recipients increases the long-term risk for carcinoma. However, there is insufficient knowledge regarding the incidence and biological behavior of papillary thyroid carcinomas (PTC) in renal allograft recipients. In the present study we examined the incidence and biological behavior of PTCs among 1739 patients transplanted between January 1986 and December 1999 who had been followed for a mean period of 137 months (range, 84-238 months). During the follow-up, 129 (7.4%) recipients were identified to display posttransplantation malignancies, including 12 (0.7%) with PTCs. The 6 male and 6 female patients had a mean age of 41 years (range, 23-57 years). Nine cases (incidentalomas) were diagnosed based on ultrasonographic (US) screening. Eight of those 9 were TNM stage I, 2 of the 3 clinical carcinomas were TNM stage IVa. During a mean follow-up of 94 months (range, 18-159 months), 2 (16.7%) PTC patients developed locoregional recurrence, but no patients showed distant metastases. These data showed that recipients had a higher incidence of PTC compared with the general Korean population (0.7% vs 0.02%). Posttransplantation PTC tended to show no difference in gender distribution, and was often associated with aggressive lymphatic metastasis. However, most incidentalomas showed favorable treatment outcomes. In conclusion, routine surveillance of the thyroid gland using US screening is recommended to ensure early detection, treatment, and favorable prognosis of PTC.

Anti-cancer effect of adenovirus p53 on human cervical cancer cell growth in vitro and in vivo

To evaluate anti-tumor effects of recombinant adenovirus p53, time-course p53, E6 expression, and cell growth inhibition were investigated in vitro and in vivo using cervical cancer cell lines such as CaSki, SiHa, HeLa, HeLaS3, C33A, and HT3. The cell growth inhibition was studied via cell count assay, MTT assay and neutral red assay. After transfecting AdCMVp53 into SiHa cells-xenografted nude mice, the transduction efficiency and anti-tumor effect were investigated for a month. The results showed that adenoviral p53 expression induced significant growth suppression on the cancer cells, in which E6 transcript was strongly repressed, and that the expression of p53 and E6 were remarkably dependent on each cell type. The transduction efficiency was highly maintained in vivo as well as in vitro, and the size of tumor was remarkably decreased in comparison with AdCMVLacZ control. The results suggest that the adenovirus-mediated p53 gene transfection was done very effectively in vitro and in vivo experiment, and the cell growth was suppressed via p53-dependent apoptotic cell death, and that the anti-tumor effect could be related to E6 and p53 expression pattern.

Synthesis and antibacterial activity of new 1beta-methylcarbapenems having the potential for intramolecular nonbonded S...O interactions

Mercaptoacetyliminothiadiazoline derivatives (19, 20) useful for the pendant moiety of 1beta-methylcarbapenem antibiotics were efficiently synthesized. Acetyl derivative (18) of 20 was submitted to X-ray analysis, and a significant nonbonded S...O close contact was recognized in the crystallographic structure. New 1beta-methylcarbapenems (5, 6) were synthesized by exploiting 19 and 20, and exhibited considerable antibacterial activities in vitro.

Enhanced levels of the aroma and flavor compound S-linalool by metabolic engineering of the terpenoid pathway in tomato fruits

The aromas of fruits, vegetables, and flowers are mixtures of volatile metabolites, often present in parts per billion levels or less. We show here that tomato (Lycopersicon esculentum Mill.) plants transgenic for a heterologous Clarkia breweri S-linalool synthase (LIS) gene, under the control of the tomato late-ripening-specific E8 promoter, synthesize and accumulate S-linalool and 8-hydroxylinalool in ripening fruits. Apart from the difference in volatiles, no other phenotypic alterations were noted, including the levels of other terpenoids such as gamma- and alpha-tocopherols, lycopene, beta-carotene, and lutein. Our studies indicate that it is possible to enhance the levels of monoterpenes in ripening fruits by metabolic engineering.

BIN2, a new brassinosteroid-insensitive locus in Arabidopsis

Brassinosteroids (BRs) play important roles throughout plant development. Although many genes have been identified that are involved in BR biosynthesis, genetic approaches in Arabidopsis have led to the identification of only one gene, BRI1, that encodes a membrane receptor for BRs. To expand our knowledge of the molecular mechanism(s) of plant steroid signaling, we analyzed many dwarf and semidwarf mutants collected from our previous genetic screens and identified a semidwarf mutant that showed little response to exogenous BR treatments. Genetic analysis of the bin2 (BR-INSENSITIVE 2) mutant indicated that the BR-insensitive dwarf phenotype was due to a semidominant mutation in the BIN2 gene that mapped to the middle of chromosome IV between the markers CH42 and AG. A direct screening for similar semidwarf mutants resulted in the identification of a second allele of the BIN2 gene. Despite some novel phenotypes observed with the bin2/+ mutants, the homozygous bin2 mutants were almost identical to the well-characterized bri1 mutants that are defective in BR perception. In addition to the BR-insensitive dwarf phenotype, bin2 mutants exhibited BR insensitivity when assayed for root growth inhibition and feedback inhibition of CPD gene expression. Furthermore, bin2 mutants displayed an abscisic acid-hypersensitive phenotype that is shared by the bri1 and BR-deficient mutants. A gene dosage experiment using triploid plants suggested that the bin2 phenotypes were likely caused by either neomorphic or hypermorphic gain-of-function mutations in the BIN2 gene. Thus, the two bin2 mutations define a novel genetic locus whose gene product might play a role in BR signaling.

In-vitro and in-vivo immunomodulatory effects of syringin

Syringin was found to possess immunomodulatory activity by which it inhibited the in-vitro immunohaemolysis of antibody-coated sheep erythrocytes by guinea-pig serum through suppression of C3-convertase of the classical complement. In this study, we examined its in-vitro and in-vivo activity on tumour necrosis factor (TNF)-alpha and nitric oxide (NO) production, CD4+ T cell and CD8+ cytotoxic T cell (CTLL-2) proliferation, and croton oil-, arachidonic acid- and fluorescein-isothiocynate (FITC)-induced mouse ear oedema model. Syringin significantly inhibited both TNF-alpha production from lipopolysaccharide (LPS)-stimulated RAW264.7 cells and CD8+ T cell (CTLL-2) proliferation in a dose-dependent manner, whereas neither NO production nor CD4+ T cell proliferation were blocked even by high concentrations of syringin. In the invivo experiments, syringin also significantly suppressed FITC-induced ear oedema in mice but not the ear oedema induced by croton or arachidonic acid. These results suggest that syringin may be implicated as an immunomodulator having an anti-allergic effect rather than an anti-inflammatory effect. The anti-allergic effect of syringin seems to be due, in part, to inhibition of TNF-alpha production and cytotoxic T cell proliferation.

CD3 polymorphism in cynomolgus monkeys (Macaca fascicularis)

Cynomolgus monkeys were divided into two groups in terms of the reactivity of their lymphocytes with the FN18 monoclonal antibody, which is directed to the CD3 of rhesus monkeys. It was shown that 24 (12.2%) out of 196 monkeys did not have lymphocytes that reacted with the FN18, although T cells from those animals responded well to mitogenic stimulation. We have determined the nucleotide sequences of the CD3delta, CD3gamma, and CD3epsilon chains and found that two amino acids of the CD3epsilon chain of the FN18 non-reactive monkeys were different when compared with the FN18 reactive monkeys. Our results indicated that the CD3epsilon molecule of cynomolgus monkeys is polymorphic at the epitope level, which is recognized by the FN18 monoclonal antibody.

Transglutaminase-mediated crosslinking of specific core histone subunits and cellular senescence

We observed that the transglutaminase (tTGase) level and activity increased in aged rats and senescent primary fibroblasts, suggesting that the tTGase-mediated macromolecule crosslinking may play a mechanistic role during aging. Although preliminary, our in vitro experiment suggests that the target of tTGase is core histones: H2A:H2B and H3:H4 are specifically crosslinked by tTGase. On the basis of these data, we postulate that the changes of DNA metabolism in association with cellular aging may be ascribed primarily to the crosslinking of core histone subunits. Further speculation awaits substantive data showing increased histone crosslinking in senescent cells and also what crosslinked histones in various DNA metabolisms may imply. At the moment, present data are sufficient to propose that tTGase is a senescence marker and it may be primarily responsible for the phenotypes associated with cellular senescence.

An investigation of the storage and biosynthesis of phenylpropenes in sweet basil

Plants that contain high concentrations of the defense compounds of the phenylpropene class (eugenol, chavicol, and their derivatives) have been recognized since antiquity as important spices for human consumption (e.g. cloves) and have high economic value. Our understanding of the biosynthetic pathway that produces these compounds in the plant, however, has remained incomplete. Several lines of basil (Ocimum basilicum) produce volatile oils that contain essentially only one or two specific phenylpropene compounds. Like other members of the Lamiaceae, basil leaves possess on their surface two types of glandular trichomes, termed peltate and capitate glands. We demonstrate here that the volatile oil constituents eugenol and methylchavicol accumulate, respectively, in the peltate glands of basil lines SW (which produces essentially only eugenol) and EMX-1 (which produces essentially only methylchavicol). Assays for putative enzymes in the biosynthetic pathway leading to these phenylpropenes localized many of the corresponding enzyme activities almost exclusively to the peltate glands in leaves actively producing volatile oil. An analysis of an expressed sequence tag database from leaf peltate glands revealed that known genes for the phenylpropanoid pathway are expressed at very high levels in these structures, accounting for 13% of the total expressed sequence tags. An additional 14% of cDNAs encoded enzymes for the biosynthesis of S-adenosyl-methionine, an important substrate in the synthesis of many phenylpropenes. Thus, the peltate glands of basil appear to be highly specialized structures for the synthesis and storage of phenylpropenes, and serve as an excellent model system to study phenylpropene biosynthesis.

Experimental autoimmune encephalomyelitis in cynomolgus monkeys

Experimental autoimmune encephalomyelitis was induced in macaques. T cell clones infiltrated into the brain lesion area were compared with those in blood. Intradermal immunization of macaques with brain white matter derived from healthy macaque in combination with pertussis toxin, induced neurological symptoms in two macaques. One died on day 25 after immunization, whereas the other survived. Gross examination of the brain from the dead macaque, showed clear hemorrhagic lesions in the white matter. Hematological analysis showed that drastic T cell response was induced in macaques immunized with white matter, but not in control macaques. Flow cytometric analysis of blood cells from the affected macaques demonstrated an increase of CD4 and CD8 T cell populations expressing the CD69 early activation marker. Single strand conformation polymorphism (SSCP) analysis of T cell receptor beta chain showed T cell clones infiltrated into the brain lesion, which were different from those found in the peripheral blood of the same monkey. The present paper shows that SSCP analysis of TCR is useful in studying clonality of T cells infiltrating into the brain tissue of macaque with EAE.

Characterization of expanded T cell clones in healthy macaques: ontogeny, distribution and stability

Peripheral expanded T cell clones have been discussed mainly in relation to certain diseases or immune function in humans and mice. There is little information on their ontogeny, stability and distribution among T cell subsets as well as major lymphoid organs. We applied reverse transcription-polymerase chain reaction (RT-PCR) with family specific primers for monkey T cell receptor beta chain V regions and single-strand conformation polymorphism (SSCP) analysis to analyze the expanded T cell clones in cynomolgus monkeys (Macaca fascicularis). A number of expanded T cell clones were detected in the peripheral blood of young and adult monkeys, but few expanded T cell clones were detected in the blood of a fetus and a 2-day-old neonate. The clones in adults were maintained over 3 months. These expanded T cell clones were distributed only in peripheral blood and spleen, but few were found in lymph nodes (axillary, inguinal and intestinal). The number of expanded T cell clones was much greater in CD8 single-positive (CD8sp) T cells than in CD4sp T cells, showing that most of these clones originated in the CD8sp T cell population. Almost all the expanded CD8sp T cell clones belonged to the CD28(-), CD29(hi) and Fas(+) subset. The usage of V beta genes was not skewed in the 24 V beta. Furthermore, higher mRNA signals for effector molecules perforin and IFN-gamma were detected in CD8sp T cell subsets with phenotypes of CD28(-), CD29(hi) and Fas(+), suggesting that the expanded T cells might have developed in relation to T cell activation in the periphery of cynomolgus monkeys.

Auxin and brassinosteroid differentially regulate the expression of three members of the 1-aminocyclopropane-1-carboxylate synthase gene family in mung bean (Vigna radiata L.)

Indole-3-acetic acid (IAA) markedly increased ethylene production by inducing the expression of three 1aminocyclopropane-1-carboxylate (ACC) synthase cDNAs (pVR-ACS1, pVR-ACS6 and pVR-ACS7) in mung bean hypocotyls. Results from nuclear run-on transcription assay and RNA gel blot studies revealed that all three genes were transcriptionally active displaying unique patterns of induction by IAA and various hormones in etiolated hypocotyls. Particularly, 24-epibrassinolide (BR), an active brassinosteroid, specifically enhanced the expression of VR-ACS7 by a distinct temporal induction mechanism compared to that of IAA. In addition, BR synergistically increased the IAA-induced VR-ACS6 and VR-ACS7 transcript levels, while it effectively abolished both the IAA- and kinetin-induced accumulation of VR-ACS1 mRNA. In light-grown plants, VR-ACS1 was induced by IAA in roots, and VR-ACS6 in epicotyls. IAA- and BR-treatments were not able to increase the VR-ACS7 transcript in the light-grown tissues. These results indicate that the expression of ACC synthase multigene family is regulated by complex hormonal and developmental networks in a gene- and tissue-specific manner in mung bean plants. The VR-ACS7 gene was isolated, and chimeric fusion between the 2.4 kb 5'-upstream region and the beta-glucuronidase (GUS) reporter gene was constructed and introduced into Nicotiana tabacum. Analysis of transgenic tobacco plants revealed the VR-ACS7 promoter-driven GUS activity at a highly localized region of the hypocotyl-root junction of control seedlings, while a marked induction of GUS activity was detected only in the hypocotyl region of the IAA-treated transgenic seedlings where rapid cell elongation occurs. Although there was a modest synergistic effect of BR on the IAA-induced GUS activity, BR alone failed to increase the GUS activity, suggesting that induction of VR-ACS7 occurs via separate signaling pathways in response to IAA and BR. A scheme of the multiple regulatory pathways for the expression of ACC synthase multigene family by auxin and BR is presented.

Characterization of benzylalcohol acetyltransferases in scented and non-scented Clarkia species

The floral scent of Clarkia breweri, an annual native to California, contains copious amounts of benzylacetate, which is synthesized by a reaction of benzylalcohol and acetyl-CoA that is catalyzed by acetyl-CoA:benzylalcohol acetyltransferase (BEAT). Here we demonstrate that different lines of C. breweri contain different levels of BEAT activity even though they have similar levels of BEAT mRNA. We also present evidence that the genome of C. breweri's non-scented progenitor, C. concinna, contains BEAT genes, but that its flowers have little BEAT enzymatic activity. This is due to the fact that although C. concinna BEAT genes are transcribed in the flowers, the single intron in these transcripts is almost never spliced out, and when the intron is spliced out, the resulting enzyme has higher affinity with substrates other than benzylalcohol. These results indicate that the regulation of BEAT activity in Clarkia involves post-transcriptional mechanisms.

S-Adenosyl-L-methionine:salicylic acid carboxyl methyltransferase, an enzyme involved in floral scent production and plant defense, represents a new class of plant methyltransferases

S-Adenosyl-L-methionine:salicylic acid carboxyl methyltransferase (SAMT) was partially purified from petals of the annual California plant Clarkia breweri. SAMT catalyzes the formation of methylsalicylate, an important floral scent compound in C. breweri, from salicylic acid and S-adenosyl-L-methionine (SAM). The native enzyme is a dimer with a subunit molecular weight of 40.3 kDa, and it has a Km for salicylic acid of 24 microM and a Km for SAM of 9 microM. A cDNA encoding SAMT was isolated from a C. breweri cDNA library prepared from floral mRNA. The sequence of the protein encoded by SAMT cDNA shows no significant sequence similarity to any protein in the data bank whose biochemical function is known. It does show significant sequence similarity (20-40% identity) to proteins encoded by at least seven Arabidopsis thaliana genes whose sequences have recently been determined in large-scale sequencing projects. The C. breweri SAMT cDNA was expressed in E. coli and the bacterial cells synthesized a functional SAMT protein with properties nearly identical to those of the plant-purified enzyme.

Effects of SIVmac infection on peripheral blood CD4+CD8+ T lymphocytes in cynomolgus macaques

We have previously reported that CD4+CD8+ double-positive (DP) T cells with a resting memory phenotype exist in a substantial proportion of peripheral blood lymphocytes of adult cynomolgus macaques. In this study, we examined the effects of simian immunodeficiency virus of macaque (SIVmac) infection on DP T cells. In vitro, SIVmac239 nef-open (239) and its nef-deletion mutant replicated well in both CD4+CD8- and DP T cells. However, when the macaques were infected with 239, DP, but not CD4+CD8-, T cells were transiently increased in parallel with cell activation and viral replication, followed by depletion within 1 month postinfection. Interestingly, the nef gene was required for depletion but not for the increase and activation of DP T cells. These data suggest that the pathogenic SIV infection may downmodulate production and/or blood circulation of DP T cells by a Nef function-related mechanism(s) different from that for the depletion of CD4+CD8- T cells.