Association between dementia diagnosis at dialysis initiation and mortality in older patients with end-stage kidney disease in South Korea

Background

The prevalence of dementia is 2- to 7-fold higher among patients with end-stage kidney disease (ESKD) than among the general population; however, its clinical implications in this population remain unclear. Therefore, this study aimed to determine whether comorbid dementia increases mortality among older patients with ESKD undergoing newly initiated hemodialysis.

Methods

We analyzed data from the Korean Society of Geriatric Nephrology retrospective cohort, which included 2,736 older ESKD patients (≥70 years old) who started hemodialysis between 2010 and 2017. Kaplan-Meier survival and Cox regression analyses were used to examine all-cause mortality between the patients with and without dementia in this cohort.

Results

Of the 2,406 included patients, 8.3% had dementia at the initiation of dialysis; these patients were older (79.6 ± 6.0 years) than patients without dementia (77.7 ± 5.5 years) and included more women (male:female, 89:111). Pre-ESKD diagnosis of dementia was associated with an increased risk of overall mortality (hazard ratio, 1.503; p < 0.001), and this association remained consistent after multivariate adjustment (hazard ratio, 1.268; p = 0.009). In subgroup analysis, prevalent dementia was associated with mortality following dialysis initiation in female patients, those aged <85 years, those with no history of cerebrovascular accidents or severe behavioral disorders, those not residing in nursing facilities, and those with no or short-term hospitalization.

Conclusion

A pre-ESKD diagnosis of dementia is associated with mortality following dialysis initiation in older Korean population. In older patients with ESKD, cognitive assessment at dialysis initiation is necessary.

Importance of dialysis specialists in early mortality in elderly hemodialysis patients: a multicenter retrospective cohort study

The early mortality rate in elderly patients undergoing hemodialysis is more than twice that in young patients, requiring more specialized healthcare. We investigated whether the number of professional dialysis specialists affected early mortality in elderly patients undergoing hemodialysis. This multicenter retrospective cohort study analyzed data from 1860 patients aged ≥ 70 years who started hemodialysis between January 2010 and December 2017. Study regions included Seoul, Gyeonggi-do, Gangwon-do, Daejeon/Chungcheong-do, Daegu/Gyeongsangbuk-do, and Busan/Ulsan/Gyeongsangnam-do. The number of patients undergoing hemodialysis per dialysis specialist was calculated using registered data from each hemodialysis center. Early mortality was defined as death within 6 months of hemodialysis initiation. Gangwon-do (28.3%) and Seoul (14.5%) showed the highest and lowest early mortality rate, respectively. Similarly, Gangwon-do (64.6) and Seoul (43.9) had the highest and lowest number of patients per dialysis specialist, respectively. Relatively consistent results were observed for the regional rankings of early mortality rate and number of patients per dialysis specialist. Multivariate Cox regression analysis-adjusted for previously known significant risk factors-revealed that the number of patients per dialysis specialist was an independent risk factor for early mortality (hazard ratio: 1.031, p < 0.001). This study underscores the growing need for dialysis specialists for elderly hemodialysis patients in Korea.

Effect of low-density lipoprotein level and mortality in older incident statin-naïve hemodialysis patients

BACKGROUND

This study aimed to analyze low-density lipoprotein cholesterol (LDL-C) levels and their relationship with mortality in order to identify the appropriate lipid profile for older Korean hemodialysis patients.

METHODS

We enrolled a total of 2,732 incident hemodialysis patients aged > 70 years from a retrospective cohort of the Korean Society of Geriatric Nephrology from 2010 Jan to 2017 Dec, which included 17 academic hospitals in South Korea. Of these patients, 1,709 were statin-naïve, and 1,014 were analyzed after excluding those with missing LDL-C level data. We used multivariate Cox regression analysis to select risk factors from 20 clinical variables among the LDL-C groups.

RESULTS

The mean age of the entire patient population was 78 years, with no significant differences in age between quartiles Q1 to Q4. However, the proportion of males decreased as the quartiles progressed towards Q4 (p < 0.001). The multivariate Cox regression analysis, which included all participants, showed that low LDL-C levels were associated with all-cause mortality. In the final model, compared to Q1, the hazard ratios (95% confidence interval) were 0.77 (0.620-0.972; p = 0.027), 0.85 (0.676-1.069; p = 0.166), and 0.65 (0.519-0.824; p < 0.001) for Q2, Q3, and Q4, respectively, after adjusting for covariates, such as conventional and age-specific risk factors. The final model demonstrated that all-cause mortality increased as LDL-C levels decreased, as confirmed by a restrictive cubic spline plot.

CONCLUSIONS

In older hemodialysis patients who had not previously received dyslipidemia treatment, elevated LDL-C levels were not associated with increased all-cause mortality. Intriguingly, lower LDL-C levels appear to be associated with an unfavorable effect on all-cause mortality among high-risk hemodialysis patients.

Comparison of the association intensity of creatinine and cystatin C with hyperphosphatemia and hyperparathyroidism in patients with chronic kidney disease

Herein, we compared the association intensity of estimated glomerular filtration rate (eGFR) equations using creatinine (Cr) or cystatin C (CysC) with hyperphosphatemia and secondary hyperparathyroidism occurrence, which reflect the physiological changes occurring during chronic kidney disease (CKD) progression. This study included 639 patients treated between January 2019 and February 2022. The patients were divided into low- and high-difference groups based on the median value of the difference between the Cr-based eGFR (eGFR_Cr) and CysC-based eGFR (eGFR_CysC). Sociodemographic and laboratory factors underlying a high difference between eGFR_Cr and eGFR_CysC were analyzed. The association intensity of eGFR_Cr, eGFR_CysC and both Cr- and CysC-based eGFR (eGFR_Cr-CysC) was compared using the area under the receiver operating characteristic curve (AuROC) values for hyperphosphatemia and hyperparathyroidism occurrence in the overall cohort and the low- and high-difference groups. Age > 70 years and CKD grade 3 based on eGFR_Cr were significant factors affecting the high differences. eGFR_CysC and eGFR_Cr-CysC showed higher AuROC values than that of eGFR_Cr, especially in the high-difference group and in patients with CKD grade 3. Our results show that CysC should be evaluated in patients with significant factors, including age > 70 years and CKD grade 3, to accurately assess kidney function to better determine the physiological changes in CKD progression and predict prognosis accurately.

Association between physical activity and risk of renal function decline and mortality in community-dwelling older adults: a nationwide population-based cohort study

BACKGROUND

Physical activity (PA) is an important risk factor associated with health outcomes. However, the relationship between PA and kidney function decline in older adults remains unclear. We examined the influence of PA on kidney function decline and mortality in community-dwelling older adults.

METHODS

Adults aged ≥ 65 years with an estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m² who had available health checkup data from 2009 to 2010 were included. The cohort was followed annually through December 2015 for anthropometric, sociodemographic, and medical information including outcomes and biennially for laboratory information from the health checkup. We divided these patients into three groups according to self-reported PA (Inactive group: no leisure-time PA, Active group: vigorous activity for at least 80 min/week or a sum of moderate-intensity activity and walking for at least 300 min/week, Low-active group: level of PA between the definitions of the other two groups). Associations between the intensity of PA and death, cardiovascular death, and ≥ 50% eGFR decline were investigated.

RESULTS

Among 102,353 subjects, 32,984 (32.23%), 54,267 (53.02%), and 15,102 (14.75%) were classified into the inactive, low-active, and active groups, respectively. The active group was younger, contained a higher proportion of men, and had higher frequencies of hypertension, diabetes mellitus, drinking, and smoking than the other groups. The active group had significantly lower incidence rates of mortality, cardiovascular mortality, and kidney function decline than the other groups (all p < 0.001). The active group also showed lower all-cause (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.70-0.82) and cardiovascular mortality (HR, 0.64; 95% CI, 0.53-0.78) and protection against ≥ 50% eGFR decline (HR, 0.81; 95% CI, 0.68-0.97) compared with the inactive group in the fully adjusted Cox proportional hazards regression model.

CONCLUSIONS

High PA was an independent modifiable lifestyle factor for reducing mortality and protecting against declines in kidney function in older adults.

A Multi-Center, Prospective Observational Study to Investigate the Safety, Compliance, and Efficacy of Omethyl QTlet Soft Capsule

Omega-3 fatty acids have been shown to be effective in lowering triglyceride (TG) levels; however, tolerability issues arise due to the large size of the pills. The purpose of this study was to examine the safety, compliance, and efficacy of Omethyl QTlet soft capsules (OQCs). This multi-center, prospective, observational study evaluated the safety, compliance, and efficacy of OQCs. Patients with hypertriglyceridemia with a history of omega-3 fatty acid intake were enrolled in this study and were prescribed OQCs (2 g−4 g/day) for eight weeks. All adverse events (AEs), adverse drug reactions (ADRs), and serious adverse events (SAEs) were recorded for safety evaluation. Adherence to treatment was assessed using questionnaires, and efficacy was assessed by changes in lipid and lipoprotein levels after eight weeks from baseline. The convenience of taking medication was analyzed for 580 patients, and the efficacy test was performed for 563 patients. The AE and ADR rates were 8.2% and 5.7%, respectively. There were only two SAEs. Of the patients, 55.8% responded that the OQC improved medication convenience, and mean changes in TG, total cholesterol, LDL-C, and non-HDL-C from baseline to eight weeks were −37.88 mg/dL, −11.56 mg/dL, −5.55 mg/dL, and −10.87 mg/dL, respectively (p-values < 0.001). In patients who had previously taken omega-3 fatty acids, OQCs showed safety and efficacy in lowering TG, and it was confirmed that compliance with medicine also improved compared to omega-3 fatty acids.

Effect of shared decision-making education on physicians' perceptions and practices of end-of-life care in Korea

Background

Evidence of the ethical appropriateness and clinical benefits of shared decision-making (SDM) are accumulating. This study aimed to not only identify physicians’ perspectives on SDM, and practices related to end-of-life care in particular, but also to gauge the effect of SDM education on physicians in Korea.

Methods

A 14-item questionnaire survey using a modified Delphi process was delivered to nephrologists and internal medicine trainees at 17 university hospitals.

Results

A total of 309 physicians completed the survey. Although respondents reported that 69.9% of their practical decisions were made using SDM, 59.9% reported that it is not being applied appropriately. Only 12.3% of respondents had received education on SDM as part of their training. The main obstacles to appropriate SDM were identified as lack of time (46.0%), educational materials and tools (29.4%), and education on SDM (24.3%). Although only a few respondents had received training on SDM, the proportion of those who thought they were using SDM appropriately in actual practice was high; the proportion of those who chose lack of time and education as factors that hindered the proper application of SDM was low.

Conclusion

The majority of respondents believed that SDM was not being implemented properly in Korea, despite its use in actual practice. To improve the effectiveness of SDM in the Korean medical system, appropriate training programs and supplemental policies that guarantee sufficient application time are required.

P0598COMPARISION OF OUTCOMES ACCORDING TO URINE CHEMISTRY TESTING TIME FOR THE CAUSES OF ACUTE KIDNEY INJURY PATIENTS ADMITTED TO THE EMERGENCY ROOM

Background and Aims

Rapid identification and treatment of acute kidney injury can help to restore kidney function. In order to differentiate between prerenal AKI and intrinsic AKI, we perform a urine chemistry test to determine the function of the renal tubule. However, there is no report that it is helpful to arrive at the hospital as early as possible and to perform these urine chemistry tests as soon as possible.

Method

We analyzed the timing of urinary chemistry in AKI patients who were admitted to our hospital through the emergency room for 3 years and divided into two groups. Early group was defined as patients who performed the test within 3 h of arrival in the emergency room. Late group was defined as patients who were late or not. The prognostic factors were change in 30 day eGFR and duration of hospital stay. We also compared the usefulness of urine chemistry test between pre renal AKI and intrinsic AKI in each group.

Results

The changes of eGFR after 30 days in each group are 41.6 ± 27.6 mL/min/1.73 m2 (Early group, n = 92) vs 30.4 ± 26.8 mL/min/1.73 m2 (Late group, n = 180) (P = 0.0013). Early group patients were discharged more quickly than patients in the late group (Hospital day: 11.5 ± 10.1 vs 13.8 ± 10.5, P = 0.0450). When analyzed according to the causes of AKI, these changes showed differences in prerenal AKI rather than intrinsic AKI(Figure).

Conclusion

A urine chemistry test is a test to help determine the cause of AKI. Based on the results of urine chemistry performed within 3 h after arrival at the hospital, patients with AKI who visited the emergency room had better improved kidney function and less hospitalization.

Apolipoprotein J is a hepatokine regulating muscle glucose metabolism and insulin sensitivity

Crosstalk between liver and skeletal muscle is vital for glucose homeostasis. Hepatokines, liver-derived proteins that play an important role in regulating muscle metabolism, are important to this communication. Here we identify apolipoprotein J (ApoJ) as a novel hepatokine targeting muscle glucose metabolism and insulin sensitivity through a low-density lipoprotein receptor-related protein-2 (LRP2)-dependent mechanism, coupled with the insulin receptor (IR) signaling cascade. In muscle, LRP2 is necessary for insulin-dependent IR internalization, an initial trigger for insulin signaling, that is crucial in regulating downstream signaling and glucose uptake. Of physiologic significance, deletion of hepatic ApoJ or muscle LRP2 causes insulin resistance and glucose intolerance. In patients with polycystic ovary syndrome and insulin resistance, pioglitazone-induced improvement of insulin action is associated with an increase in muscle ApoJ and LRP2 expression. Thus, the ApoJ-LRP2 axis is a novel endocrine circuit that is central to the maintenance of normal glucose homeostasis and insulin sensitivity.

Hepatokines are proteins secreted by the liver that can regulate whole body metabolism. Here the authors identify apolipoprotein J as a hepatokine that regulates muscle glucose metabolism and insulin resistance through a low-density lipoprotein receptor-related protein−2 mediated mechanism in mice.

Metformin Ameliorates Lipotoxic β-Cell Dysfunction through a Concentration-Dependent Dual Mechanism of Action

BACKGROUND

Chronic exposure to elevated levels of free fatty acids contributes to pancreatic β-cell dysfunction. Although it is well known that metformin induces cellular energy depletion and a concomitant activation of AMP-activated protein kinase (AMPK) through inhibition of the respiratory chain, previous studies have shown inconsistent results with regard to the action of metformin on pancreatic β-cells. We therefore examined the effects of metformin on pancreatic β-cells under lipotoxic stress.

METHODS

NIT-1 cells and mouse islets were exposed to palmitate and treated with 0.05 and 0.5 mM metformin. Cell viability, glucose-stimulated insulin secretion, cellular adenosine triphosphate, reactive oxygen species (ROS) levels and Rho kinase (ROCK) activities were measured. The phosphorylation of AMPK was evaluated by Western blot analysis and mRNA levels of endoplasmic reticulum (ER) stress markers and NADPH oxidase (NOX) were measured by real-time quantitative polymerase chain reaction analysis.

RESULTS

We found that metformin has protective effects on palmitate-induced β-cell dysfunction. Metformin at a concentration of 0.05 mM inhibits NOX and suppresses the palmitate-induced elevation of ER stress markers and ROS levels in a AMPK-independent manner, whereas 0.5 mM metformin inhibits ROCK activity and activates AMPK.

CONCLUSION

This study suggests that the action of metformin on β-cell lipotoxicity was implemented by different molecular pathways depending on its concentration. Metformin at a usual therapeutic dose is supposed to alleviate lipotoxic β-cell dysfunction through inhibition of oxidative stress and ER stress.

Rho-kinase/AMPK axis regulates hepatic lipogenesis during overnutrition

Obesity is a major risk factor for developing nonalcoholic fatty liver disease (NAFLD). NAFLD is the most common form of chronic liver disease and is closely associated with insulin resistance, ultimately leading to cirrhosis and hepatocellular carcinoma. However, knowledge of the intracellular regulators of obesity-linked fatty liver disease remains incomplete. Here we showed that hepatic Rho-kinase 1 (ROCK1) drives obesity-induced steatosis in mice through stimulation of de novo lipogenesis. Mice lacking ROCK1 in the liver were resistant to diet-induced obesity owing to increased energy expenditure and thermogenic gene expression. Constitutive expression of hepatic ROCK1 was sufficient to promote adiposity, insulin resistance, and hepatic lipid accumulation in mice fed a high-fat diet. Correspondingly, liver-specific ROCK1 deletion prevented the development of severe hepatic steatosis and reduced hyperglycemia in obese diabetic (ob/ob) mice. Of pathophysiological significance, hepatic ROCK1 was markedly upregulated in humans with fatty liver disease and correlated with risk factors clustering around NAFLD and insulin resistance. Mechanistically, we found that hepatic ROCK1 suppresses AMPK activity and a ROCK1/AMPK pathway is necessary to mediate cannabinoid-induced lipogenesis in the liver. Furthermore, treatment with metformin, the most widely used antidiabetes drug, reduced hepatic lipid accumulation by inactivating ROCK1, resulting in activation of AMPK downstream signaling. Taken together, our findings establish a ROCK1/AMPK signaling axis that regulates de novo lipogenesis, providing a unique target for treating obesity-related metabolic disorders such as NAFLD.

Developing the Korean Association of Medical Colleges graduate outcomes of basic medical education based on "the role of Korean doctor, 2014"

The Korean Association of Medical Colleges (KAMC) developed graduate outcomes based on "The role of Korean doctor, 2014" to serve as guidelines regarding outcome-based education in Korea. The working group in this study analyzed 65 competencies proposed in "The role of Korean doctor, 2014" according to the developmental principle that certain outcomes should be demonstrated at the point of entry into the graduate medical education. We established 34 competencies as "preliminary graduate outcomes" (PGOs). The advisory committee consisted of 11 professors, who reviewed the validity of PGOs. Ultimately, a total of 19 "revised graduate outcomes" (RGOs) were selected. We modified the RGOs based on opinions from medical schools and a public hearing. In November 2017, the KAMC announced the "graduate outcomes for basic medical education," which serves as a guide for basic medical education for the 40 medical schools throughout Korea. Medical schools can expand the graduate outcomes according to their educational goals and modify them according to their own context. We believe that graduate outcomes can be a starting point for connecting basic medical education to graduate medical education.

Extract of Rhus verniciflua stokes protects against renal ischemia-reperfusion injury by enhancing Nrf2-mediated induction of antioxidant enzymes

Ischemia-reperfusion injury (IRI) may cause acute kidney disease (AKD) by mediating the oxidative stress-induced apoptosis of parenchymal cells. The extract of Rhus verniciflua Stokes (RVS) is used as a traditional herbal medicine as it exhibits anti-oxidant, anti-apoptotic and anti-inflammatory properties. Therefore, the current study investigated the therapeutic effect and the underlying mechanism of RVS on IRI-induced AKD in vivo and in vitro. The current study assessed the effects of RVS on a mouse model of renal IRI and in hypoxic human renal tubular epithelial HK-2 cells. The results demonstrated that the IRI-induced elevation of blood urea nitrogen, serum creatinine and lactate dehydrogenase was significantly attenuated by the intraoral administration of RVS (20 mg/kg/day) for 14 days prior to surgery. It was demonstrated that IRI surgery induced histological damage and cellular apoptosis in renal parenchyma, which were attenuated by pretreatment with RVS. Furthermore, in HK-2 cells incubated with 300 µM CoCl₂ to induce chemical hypoxia, it was demonstrated that RVS treatment significantly inhibited cell death and the production of reactive oxygen species (ROS). Furthermore, RVS treatment upregulated the levels of endogenous antioxidant enzymes, including heme oxygenase-1 and catalase, as well as their upstream regulator nuclear factor erythroid 2-related factor 2, in HK-2 cells. Taken together, these results suggested that the intraoral administration of RVS induces a therapeutic effect on IRI-induced AKD. These effects are at least partly due to the attenuation of ROS production via upregulation of the antioxidant defense system in renal tubular cells.

Circulating ApoJ is closely associated with insulin resistance in human subjects

OBJECTIVE

Insulin resistance is a major risk factor for type 2 diabetes. ApolipoproteinJ (ApoJ) has been implicated in altered pathophysiologic states including cardiovascular and Alzheimer's disease. However, the function of ApoJ in regulation of glucose homeostasis remains unclear. This study sought to determine whether serum ApoJ levels are associated with insulin resistance in human subjects and if they change after interventions that improve insulin sensitivity.

METHODS

Serum ApoJ levels and insulin resistance status were assessed in nondiabetic (ND) and type 2 diabetic (T2D) subjects. The impacts of rosiglitazone or metformin therapy on serum ApoJ levels and glucose disposal rate (GDR) during a hyperinsulinemic/euglycemic clamp were evaluated in a separate cohort of T2D subjects. Total ApoJ protein or that associated with the HDL and LDL fractions was measured by immunoblotting or ELISA.

RESULTS

Fasting serum ApoJ levels were greatly elevated in T2D subjects (ND vs T2D; 100±8.3 vs. 150.6±8.5AU, P<0.0001). Circulating ApoJ levels strongly correlated with fasting glucose, fasting insulin, HOMA-IR, and BMI. ApoJ levels were significantly and independently associated with HOMA-IR, even after adjustment for age, sex, and BMI. Rosiglitazone treatment in T2D subjects resulted in a reduction in serum ApoJ levels (before vs. after treatment; 100±13.9 vs. 77±15.2AU, P=0.015), whereas metformin had no effect on ApoJ levels. The change in ApoJ levels during treatment was inversely associated with the change in GDR. Interestingly, ApoJ content in the LDL fraction was inversely associated with HOMA-IR.

CONCLUSION

Serum ApoJ levels are closely correlated with the magnitude of insulin resistance regardless of obesity, and decrease along with improvement of insulin resistance in response only to rosiglitazone in type 2 diabetes.

Effects of Short-Term Exenatide Treatment on Regional Fat Distribution, Glycated Hemoglobin Levels, and Aortic Pulse Wave Velocity of Obese Type 2 Diabetes Mellitus Patients

BACKGROUND

Most type 2 diabetes mellitus patients are obese and have obesity related vascular complications. Exenatide treatment is well known for both decreasing glycated hemoglobin levels and reduction in body weight. So, this study aimed to determine the effects of exenatide on body composition, glycated hemoglobin levels, and vascular stiffness in obese type 2 diabetes mellitus patients.

METHODS

For 1 month, 32 obese type 2 diabetes mellitus patients were administered 5 μg of exenatide twice daily. The dosage was then increased to 10 μg. Patients' height, body weight, glycated hemoglobin levels, lipid profile, pulse wave velocity (PWV), body mass index, fat mass, and muscle mass were measured by using Inbody at baseline and after 3 months of treatment.

RESULTS

After 3 months of treatment, glycated hemoglobin levels decreased significantly (P=0.007). Triglyceride, total cholesterol, and low density lipoprotein levels decreased, while aspartate aminotransferase and alanine aminotransferase levels were no change. Body weight, and fat mass decreased significantly (P=0.002 and P=0.001, respectively), while interestingly, muscle mass did not decrease (P=0.289). In addition to, Waist-to-hip ratio and aortic PWV decreased significantly (P=0.006 and P=0.001, respectively).

CONCLUSION

Effects of short term exenatide use in obese type 2 diabetes mellitus with cardiometabolic high risk patients not only reduced body weight without muscle mass loss, body fat mass, and glycated hemoglobin levels but also improved aortic PWV in accordance with waist to hip ratio.

An Adult Case of Bartter Syndrome Type III Presenting with Proteinuria

Bartter syndrome (BS) I–IV is a rare autosomal recessive disorder affecting salt reabsorption in the thick ascending limb of the loop of Henle. This report highlights clinicopathological findings and genetic studies of classic BS in a 22-year-old female patient who presented with persistent mild proteinuria for 2 years. A renal biopsy demonstrated a mild to moderate increase in the mesangial cells and matrix of most glomeruli, along with marked juxtaglomerular cell hyperplasia. These findings suggested BS associated with mild IgA nephropathy. Focal tubular atrophy, interstitial fibrosis, and lymphocytic infiltration were also observed. A genetic study of the patient and her parents revealed a mutation of the CLCNKB genes. The patient was diagnosed with BS, type III. This case represents an atypical presentation of classic BS in an adult patient. Pathologic findings of renal biopsy combined with genetic analysis and clinicolaboratory findings are important in making an accurate diagnosis.

Omega-3 Polyunsaturated Fatty Acids May Attenuate Streptozotocin-Induced Pancreatic β-Cell Death via Autophagy Activation in Fat1 Transgenic Mice

BACKGROUND

Inflammatory factors and β-cell dysfunction due to high-fat diets aggravate chronic diseases and their complications. However, omega-3 dietary fats have anti-inflammatory effects, and the involvement of autophagy in the etiology of diabetes has been reported. Therefore, we examined the protective effects of autophagy on diabetes using fat-1 transgenic mice with omega-3 self-synthesis capability.

METHODS

Streptozotocin (STZ) administration induced β-cell dysfunction in mice; blood glucose levels and water consumption were subsequently measured. Using hematoxylin and eosin (H&E) and Masson's trichrome staining, we quantitatively assessed STZ-induced changes in the number, mass, and fibrosis of pancreatic islets in fat-1 and control mice. We identified the microtubule-associated protein 1A/1B light chain 3-immunoreactive puncta in β-cells and quantified p62 levels in the pancreas of fat-1 and control mice.

RESULTS

STZ-induced diabetic phenotypes, including hyperglycemia and polydipsia, were attenuated in fat-1 mice. Histological determination using H&E and Masson's trichrome staining revealed the protective effects of the fat-1 expression on cell death and the scarring of pancreatic islets after STZ injection. In the β-cells of control mice, autophagy was abruptly activated after STZ treatment. Basal autophagy levels were elevated in fat-1 mice β-cells, and this persisted after STZ treatment. Together with autophagosome detection, these results revealed that n-3 polyunsaturated fatty acid (PUFA) enrichment might partly prevent the STZ-related pancreatic islet damage by upregulating the basal activity of autophagy and improving autophagic flux disturbance.

CONCLUSION

Fat-1 transgenic mice with a n-3 PUFA self-synthesis capability exert protective effects against STZ-induced β-cell death by activating autophagy in β-cells.

Attenuation of streptozotocin-induced pancreatic beta cell death in transgenic fat-1 mice via autophagy activation

BACKGROUND

The incidence of diabetes has rapidly increased due to changes in eating habits. Inflammatory factors and beta (β) cell dysfunction due to high-fat diets aggravate chronic diseases and their complications. However, omega-3 dietary fats have anti-inflammatory effects, and the involvement of autophagy in the etiology of diabetes has been reported. Therefore, we examined the protective effects of autophagy on diabetes using fat-1 transgenic mice with omega-3 self-synthesis capability.

METHODS

Streptozotocin (STZ) administration induced β cell dysfunction in mice; blood glucose levels and water consumption were subsequently measured. Using hematoxylin and eosin (H&E) and Masson's trichrome staining, we quantitatively assessed STZ-induced changes in the number, mass, and fibrosis of pancreatic islets in fat-1 and control mice. We identified the microtubule-associated protein 1A/1B light chain 3-immunoreactive puncta in β cells and quantified p62 levels in the pancreas of fat-1 and control mice.

RESULTS

STZ-induced diabetic phenotypes, including hyperglycemia and polydipsia, were attenuated in fat-1 mice. Histological determination using H&E and Masson's trichrome staining revealed the protective effects of the fat-1 mutation on cell death and the scarring of pancreatic islets after STZ injection. In the β cells of control mice, autophagy was abruptly activated after STZ treatment. Basal autophagy levels were elevated in fat-1 mice β cells, and this persisted after STZ treatment. Together with autophagosome detection, these results revealed that n-3 PUFA enrichment might partly prevent the STZ-related pancreatic islet damage by upregulating the basal activity of autophagy and improving autophagic flux disturbance.

CONCLUSION

Fat-1 transgenic mice with a n-3 PUFA self-synthesis capability exert protective effects against STZ-induced β cell death by activating autophagy in β cells.

Is there a difference in the prevalence of gastroesophageal reflux disease between peritoneal dialysis and hemodialysis patients?

BACKGROUND/AIMS

Gastroesophageal reflux disease (GERD) is a common upper gastrointestinal disorder in patients with chronic kidney disease (CKD). However, little is known about the prevalence of GERD in dialysis patients. The aim of the present study was to investigate the difference in the prevalence of GERD in peritoneal dialysis and hemodialysis patients.

METHODS

From July 2010 to August 2011, peritoneal dialysis patients (n=30) and hemodialysis patients (n=38) were enrolled. The prevalences of GERD were assessed at a single center with endoscopic findings and interviews using a questionnaire. Also, risk factors of GERD were evaluated.

RESULTS

The prevalences of GERD in peritoneal dialysis and hemodialysis patients were 33.3% and 39.5% (p=0.748), respectively. The prevalences of erosive reflux esophagitis (ERD) in peritoneal dialysis and hemodialysis patients were 16.7% and 23.7% (p=0.477), respectively. The prevalences of nonerosive reflux disease (NERD) in peritoneal dialysis and hemodialysis patients were 16.7% and 13.2% (p=0.685), respectively. The prevalences of GERD, ERD and NERD were higher than those of the general population. The risk factor for GERD was age in hemodialysis patients.

CONCLUSIONS

The prevalence of GERD in dialysis patients was higher than that in the general population. However, there was no significant difference between peritoneal dialysis and hemodialysis patients.

Salviae radix extract prevents cisplatin-induced acute renal failure in rabbits

The present study was carried out to determine if salviae radix extract (SRE) exerts a beneficial effect against cisplatin-induced renal failure in rabbits. Rabbits were pretreated with SRE orally for 7 days, followed by cisplatin injection (5 mg/kg i.p.). Cisplatin injection caused a reduction in GFR, which was accompanied by an increase in serum creatinine levels. The fractional Na+ excretion was increased by cisplatin injection. PAH uptake by renal cortical slices was inhibited by the administration of cisplatin. Such changes were prevented by SRE pretreatment. Cisplatin injection increased lipid peroxidation, which was prevented by SRE pretreatment. The protective effect of SRE was supported by morphological studies. Cisplatin injection reduced renal blood flow that was not affected by SRE pretreatment. Cisplatin treatment in vitro in renal cortical slices increased LDH release and lipid peroxidation, which were prevented by 0.05% SRE. These results indicate that lipid peroxidation plays a critical role in cisplatin-induced acute renal failure. SRE exerts a protective effect against renal cell injury induced by cisplatin, and its effect may be attributed to its antioxidant action. However, the underlying mechanism by which SRE has antioxidant action remains to be defined.

Application of hydrostatic pressure facilitates ex vivo adenovirus gene transfer into rabbit aortas

We investigated whether application of hydrostatic pressure facilitates ex vivo adenovirus gene transfer into rabbit aortas. Assay of beta-galactosidase activity was performed in the aortas subjected to adenovirus encoding LacZ gene (Ad-LacZ) transfer. Application of hydrostatic pressure at 8 atmospheres during Ad-LacZ gene transfer (10(10) pfu/mL, 10 min) to aortic segments resulted in an approximately 4.5-fold increase in transgene efficiency. X-Gal staining showed predominant beta-galactosidase activity in the endothelial and the adventitial cells in the aorta subjected to pressure-supported Ad-LacZ gene transfer. Then we examined the effect of heme oxygenase-1 (HO-1), which catabolizes heme to carbon monoxide and biliverdin, by transferring adenovirus encoding HO-1 (Ad-HO-1) into rabbit aortas using this pressurization system. The Ad-HO-1-infected aortic segment showed a significantly decreased contractile response to phenylephrine compared to the Ad-LacZ-infected aortic segment. Pressure-supported adenovirus gene transfer may increase the feasibility of exploiting intraoperative adenovirus-mediated gene transfer.