Applicability of chronic kidney disease epidemiology collaboration equations in a Chinese population.

BACKGROUND: Accurate estimated glomerular filtration rates (eGFR) is an important step in the diagnosis of chronic kidney disease (CKD). The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, based on creatinine alone (eGFRcr), was developed to improve on the Modification of Diet in Renal Disease equation, in particular by addressing the systematic underestimation of high GFR. Whether the CKD-EPI equation, based on cystatin C alone (eGFRcys), or the combined creatinine-cystatin C CKD-EPI equation (eGFRcr-cys C), actually perform better than the CKD-EPI equation based on creatinine (eGFRcr) remains unknown, especially in Asians including Chinese populations, where eGFR equations may overestimate true GFR. METHODS: A standard dual plasma sampling method (DPSM) of estimating (99m)Tc-diethylene triamine penta-acetic acid clearance was used to determine the reference or measured GFR (mGFR). Linear regression analysis, Bland-Altman analysis, bias, absolute bias and accuracy (P30) were used to compare the performance of the combined creatinine-cystatin C equation (eGFRcr-cys) and equations based on each marker alone (eGFRcr and eGFRcys) in Chinese subjects, including both patients with CKD and healthy individuals. RESULTS: We enrolled 617 Chinese participants (49.11% female, 47.11 ± 17.25 years old), with a mean mGFR of 73.80 ± 37.55 mL/min/1.73 m(2). The predictive abilities (r), the accuracy (P15, P30, P50), bias and absolute bias of the eGFRcr-cys equation were superior to eGFRcr equation and the eGFRcys equation in overall samples. Bland-Altman analysis also demonstrated a consistent result. When compared in subgroups, the accuracy (P30) of all three equations exceeded 90% at mGFR ≥90 mL/min/1.73m(2); the eGFRcr-cys equation had the highest accuracy (P30: 95.56%). At mGFR 60-89 mL/min/1.73 m(2), the accuracies (P30) of the eGFRcr-cys and eGFRcr equations exceeded the acceptable level (≥70%), and there was no significant difference between them (P = 0.58). At mGFR <60 mL/min/1.73 m(2), the accuracy (P30) of all three equations was below 70%, but the eGFRcr-cys equation had the greatest precision. CONCLUSIONS: The performances of the eGFRcr-cys and eGFRcr equations were similar to superior to that of the eGFRcys equation at higher GFR levels in an Asian population, especially in normal and mild to moderate kidney disease. Further improvement is needed for these equations at GFR <60 mL/min per 1.73 m(2).

[Effects of Biochar Application on Soil Organic Nitrogen Component and Active Nitrogen in Eucalyptus Plantations After Five Years in Northern Guangxi].

The objective of this study was to research the characteristics of fractions of organic nitrogen and active nitrogen and their relationship under different biochar applications and to provide a basis for the preparation and practical application of biochar from Eucalyptus forest wastes. In a long-term positioning test of biochar application from 2017, six different treatments were selected:0(CK), 0.5%(T1), 1%(T2), 2%(T3), 4%(T4), and 6%(T5). The contents of soil organic nitrogen components, total nitrogen(TN), dissolved organic nitrogen(DON), and microbial biomass nitrogen(MBN) following the different treatments were measured. The results showed that:① compared with that of the control, with the increase in biochar application, the contents of soil TN, acidolysis of total organic nitrogen(AHON), ammonia nitrogen(AN), amino acid nitrogen(AAN), MBN, DON, and nitrogen storage(NS) increased significantly by 45.48%-156.32%, 44.31%-171.31%, 38.06%-223.37%, 39.42%-163.32%, 36.72%-109%, 23.27%-113.51%, and 29.45%-62.37%, respectively. The contents of soil hydrolyzable unknown nitrogen(HUN) and non-hydrolyzable nitrogen(NHN) also increased significantly by 88.41%-158.71% and 50.24%-139.01%, respectively. The contents of soil amino sugar nitrogen(ASN) decreased by 7.72%-32.73%. The contents of different forms of organic nitrogen fractions in all treatments displayed an order of AN > AAN > NHN > HUN > ASN. Compared with the no biochar treatment, each biochar treatment increased the contents and proportion of AHON in the TN. ② With the exception of HUN, the contents of other soil organic nitrogen components and active nitrogen content decreased with the increase in soil depth. ③ There were significantly positive correlations between TN, MBN, and DON and AHON, NHN, and NS contents. The principal component analysis showed that bulk density and ASN and TN and HUN, AAN, DON, and AHON were closely related, respectively. In conclusion, the application of forestry waste biochar for five years could significantly increase the content of soil organic nitrogen component and active nitrogen, thereby improving the capacity of the soil to supply nitrogen. AHON, AN, and AAN were the main factors contributing to soil active nitrogen content.

[Effects of Biochar Application on Soil Organic Carbon Component in Eucalyptus Plantations After Five Years in Northern Guangxi].

To investigate the effects of biochar(BC) addition on soil organic carbon(SOC) contents and its fractions under different biochar applications, Eucalyptus waste twigs in Northern Guangxi were used to produce BC at 500℃. Additionally, we sought to clarify and define the carbon sequestration potential of soil and provide a basis for the preparation of biochar from Eucalyptus forest wastes and soil improvement. In a long-term positioning test of biochar application from 1997, six different treatments were selected:0(CK), 0.5%(T1), 1%(T2), 2%(T3), 4%(T4), and 6%(T5). The contents of SOC, light fraction organic carbon(LFOC), heavy fraction organic carbon(HFOC), easily oxidized organic carbon(EOC), dissolved organic carbon(DOC), particulate organic carbon(POC), microbial biomass carbon(MBC), and carbon stock(CS) following the different treatments were measured. The results showed that:① compared to that in the control, biochar application induced an increase in each soil organic carbon fraction with increasing application rate and reached a maximum under the T4 or T5 treatments; with the increase in biochar application, the contents of SOC, DOC, EOC, POC, MBC, and CS increased significantly by 101.62%, 67.46%, 143.03%, 164.78%, 110.88%, and 41.73%, respectively. ② The contents of LFOC and HFOC in the 0-10, 10-20, and 20-30 cm soil layers increased significantly by 41.41%-140.63%, 9.26%-87.04%, and -19.54%-106.90% and 15.32%-78.99%, 15.72%-75.25%, and 89.49%-148.64%, respectively, with the increase in biochar application. The average contents of LFOC and HFOC in the 0-30 cm soil layer also increased gradually. The soil carbon pool of the Eucalyptus forest was dominated by a relatively stable heavy fraction organic carbon. ③ The contents of carbon stock, soil organic carbon, and its fractions decreased with the increase in soil depth. In conclusion, the application of forestry waste biochar for five years could significantly increase the content of SOC and its components, thereby increasing soil organic carbon activity. Therefore, increasing the amount of biochar was an effective measure to enhance the carbon storage, soil stable carbon pool, and soil quality of the Eucalyptus plantation field. This study provides a reference for the resource utilization of forestry waste and improvements in soil fertility of Eucalyptus plantations.

Effects of argatroban as an anticoagulant for intermittent veno-venous hemofiltration (IVVH) in patients at high risk of bleeding.

BACKGROUND: The critically ill patients with acute renal failure (ARF) undergoing intermittent veno-venous hemofiltration (IVVH) are often at high risk of bleeding. No conventional anticoagulants can adequately achieve this task. Argatroban, a synthetic direct thrombin inhibitor, has been approved for the treatment of hemodialysis patients with antithrombin III deficiency and particularly for heparin-induced thrombocytopenia II patients. Therefore, the anticoagulating effect of argatroban in patients with a high risk of bleeding was investigated. METHODS: One hundred and one ARF patients at high risk of bleeding were treated with predilution IVVH, assigned to a nonheparin group (n = 44) and an argatroban group (n = 57). Venous blood was collected to monitor the change of coagulant parameters pre- and post-IVVH in both groups. Activated partial thromboplastin time (APTT) value was monitored in the argatroban group at different sites and time points to adjust the dosage during IVVH. RESULTS: All the patients in the argatroban group completed treatment successfully, whereas in the nonheparin group, clotting of the extracorporeal circuit occurred in 16.9% of patients. Furthermore, D-dimer increased slightly and platelet counts decreased post-hemofiltration in the nonheparin group. No change was found in platelet counts and coagulant parameters in the argatroban group pre- and post-hemofiltration. Argatroban prolonged the APTT by 50% at the venous site after the initial bolus and the maintenance infusion at 2 and 4 h during the treatment with no change at the arterial site. No major bleeding episodes and serious side effects were found. CONCLUSIONS: In critically ill patients with a high risk of bleeding, argatroban is an effective and safe anticoagulant for IVVH.

Change of glomerular filtration rate in healthy adults with aging.

AIM: In order to determine the relationship between glomerular filtration rate (GFR) and age, the associated factors, and the accurate method of GFR in healthy adults, we conducted a cross-sectional study in community-dwelling adults in Beijing. METHODS: Renal function of 201 clinically healthy subjects was determined using technetium-99 m-labelled diethylene triamine pentacetic acid ((99m)Tc-DTPA). Estimated GFR was calculated with the Cockcroft-Gault (CG) equation, abbreviated Modification of Diet in Renal Disease (MDRD) equation, and plasma clearance of creatinine (Ccr). Serum cystatin C, biomarkers of inflammatory and endothelial cells were analyzed as well. Protein intake, carotid artery intima-media thickness and plaque formation were assayed as well. RESULTS: Glomerular filtration rate was negatively associated with age and the correlation coefficient for (99m)Tc-GFR, CG-GFR, MDRD-GFR, Ccr were -0.643, -0.736, -0.55 and -0.619, respectively (P < 0.001), while the correlation coefficient between cystatin C and age was 0.681 (P < 0.001). Estimated GFR were associated with measured GFR, and the correlation coefficient for Ccr, CG-GFR and MDRD-GFR were 0.813, 0.582 and 0.418, respectively (P < 0.001). The area under the receiver-operator curve of Ccr was larger, CG was smaller while MDRD was the smallest, and the difference was significant (P < 0.001). So a predicted equation was presented by cystatin C and C-reactive protein for the elderly. CONCLUSION: In the clinically healthy adults, GFR declined with age. MDRD and CG equation are not suitable to estimate GFR in healthy adults. The predicted equation established by cystatin C and C-reactive protein may be more accurate.

Anti-inflammatory renoprotective effect of clopidogrel and irbesartan in chronic renal injury.

Recent evidence suggests that platelet activation and angiotensin II may each contribute to glomerular inflammation and fibrosis. Clopidogrel inhibits platelet activation and may also reduce inflammation. This study investigated the anti-inflammatory and renoprotective effects of clopidogrel and irbesartan in the five-sixths nephrectomy rat model of chronic kidney disease. After 8 wk of treatment, 24-h proteinuria, serum creatinine, and histologic scores of glomerular sclerosis and tubulointerstitial damage were significantly lower in treated compared with untreated rats. Clopidogrel/irbesartan combination therapy had greater effects than either drug alone. Rats that underwent five-sixths nephrectomy had higher markers of platelet activation (plasma GMP-140 and renal cortical fibrin deposition) than sham-operated rats, and clopidogrel attenuated these effects. Clopidogrel and irbesartan similarly reduced the accumulation of ED-1-expressing macrophages in the cortical glomeruli and the interstitium. Combination therapy almost completely abolished macrophage infiltration and attenuated the expression of monocyte chemoattractant protein-1, intercellular adhesion molecule-1, TGF-beta(1), and connective tissue growth factor. In conclusion, combination treatment with clopidogrel and irbesartan, more so than either alone, decreases early renal injury induced by five-sixths nephrectomy by inhibiting renal inflammation.

Comparative evaluation of technetium-99m-diethylenetriaminepentaacetic acid renal dynamic imaging versus the Modification of Diet in Renal Disease equation and the Chronic Kidney Disease Epidemiology Collaboration equation for the estimation of GFR.

PURPOSE: We compared the performance of technetium-99m-diethylenetriaminepentaacetic acid (99mTc-DTPA) renal dynamic imaging (RDI), the MDRD equation, and the CKD EPI equation to estimate glomerular filtration rate (GFR). METHODS: A total of 551 subjects, including CKD patients and healthy individuals, were enrolled in this study. Dual plasma sample clearance method of 99mTc-DTPA was used as the true value for GFR (tGFR). RDI and the MDRD and CKD EPI equations for estimating GFR were compared and evaluated. RESULTS: Data indicate that RDI and the MDRD equation underestimated GFR and CKD EPI overestimated GFR. RDI was associated with significantly higher bias than the MDRD and CKD EPI equations. The regression coefficient, diagnostic precision, and consistency of RDI were significantly lower than either equation. RDI and the MDRD equation underestimated GFR to a greater degree in subjects with tGFR ≥ 90 ml/min/1.73 m2 compared with the results obtained from all subjects. In the tGFR60-89 ml/min/1.73 m2 group, the precision of RDI was significantly lower than that of both equations. In the tGFR30-59 ml/min/1.73 m2 group, RDI had the least bias, the most precision, and significantly higher accuracy compared with either equation. In tGFR < 30 ml/min/1.73 m2, the three methods had similar performance and were not significantly different. CONCLUSIONS: RDI significantly underestimates GFR and performs no better than MDRD and CKD EPI equations for GFR estimation; thus, it should not be recommended as a reference standard against which other GFR measurement methods are assessed. However, RDI better estimates GFR than either equation for individuals in the tGFR30-59 ml/min/1.73 m2 group and thus may be helpful to distinguish stage 3a and 3b CKD.

The role of complement activation in rhabdomyolysis-induced acute kidney injury.

Rhabdomyolysis (RM) may cause kidney damage and results primarily in acute kidney injury (AKI). Complement is implicated in the pathogenesis of renal diseases and ischemia-reperfusion injury (IRI), but the role of complement, especially its activation pathway(s) and its effect in RM-induced AKI, is not clear. This study established a rat model of AKI induced by RM via intramuscular treatment with glycerol. Cobra venom factor (CVF) was administered via tail vein injection to deplete complement 12 h prior to intramuscular injection of glycerol. We found that the complement components, including complement 3 (C3), C1q, MBL-A, factor B(fB), C5a, C5b-9, and CD59, were significantly increased in rat kidneys after intramuscular glycerol administration. However, the levels of serum BUN and Cr, renal tubular injury scores, and the number of TUNEL-positive cells decreased significantly in the CVF+AKI group. These results suggest that complement plays an important role in RM-induced AKI and that complement depletion may improve renal function and decrease renal tissue damage by reducing the inflammatory response and apoptosis.

Penehyclidine Hydrochloride Pretreatment Ameliorates Rhabdomyolysis-Induced AKI by Activating the Nrf2/HO-1 Pathway and Alleviating [corrected] Endoplasmic Reticulum Stress in Rats. The.

Acute kidney injury (AKI) is one of the most severe complications of rhabdomyolysis (RM). The underlying mechanisms and potential preventions need to be investigated. Penehyclidine hydrochloride (PHC) was reported to ameliorate renal ischemia-reperfusion injury, but the effect of PHC on RM-reduced AKI is unknown. In this study, we established a rat model of RM-induced AKI using an intramuscular glycerol injection in the hind limbs. Rats were pretreated with PHC before the glycerol injection, and the heme oxygenase-1 (HO-1) inhibitor ZnPP was introduced to evaluate the effect of HO-1 on RM-induced AKI. PHC pretreatment ameliorated the pathological renal injury and renal dysfunction, and decreased the renal apoptosis rate in RM-induced AKI. PHC significantly up-regulated HO-1 expression, increased HO-1 enzymatic activity and decreased the accumulation of myoglobin in renal tissues. This effect was partly inhibited by ZnPP. PHC pretreatment also effectively up-regulated nuclear factor erythroid 2-related factor 2 (Nrf2) and down-regulated glucose regulated protein 78 (GRP78) and caspase-12 at both the gene and protein levels. These results suggest that the protective effects of PHC pretreatment on RM-induced AKI occur at least in part through activating the Nrf2/HO-1 pathway and alleviating endoplasmic reticulum stress (ERS) in rat renal tissues.

Effect of steady and oscillatory shear stress on F-actin content and distribution in neutrophils.

We investigated neutrophil activation, specifically F-actin content and distribution, in situations mimicking the in vivo environment using steady and oscillatory shear. Under low steady shear (<150 s(-1)) F-actin levels were decreased for both treated (n-formyl-L-methioryl-L-leucyl-L-phenylalanine (fMLP)) and untreated neutrophils. The F-actin content increased with a change to higher steady shear levels. Neutrophils show the same behavior of decreased F-actin content for oscillatory shear (26.7 s(-1)) as they did for steady shear. In both situations, the low shear levels caused a decrease in F-actin content. However, as the magnitude of the shear rate increased, cells showed a reversal to increasing F-actin content. Shear caused a decrease in F-actin in the cell cortex for both control and fMLP treated cells. Ctyochalasin B (CB), a common F-actin assembly blocker, significantly decreased F-actin content. The results indicate that neutrophils regulate their actin network based on the level and type of shear stress they encounter in the bloodstream.

Age-related change in kidney function, its influencing factors, and association with asymptomatic carotid atherosclerosis in healthy individuals--a 5-year follow-up study.

OBJECTIVES: To better define the longitudinal changes in renal function, to examine the associated risk factors, and to investigate whether there is an independent association of decline in renal function with presence of carotid plaque in a middle-aged and elderly healthy population. METHODS: 245 healthy individuals (98 males, 147 females) evaluated at baseline and 5 years later. RESULTS: Over five years, estimated glomerular filtration rate (eGFR) decreased from 98.1±15.6 to 90.4±17.3mL/min/1.73m(2). There are three kinds of change in eGFR (elevated, stable and decreased) during follow-up, accounting for 14%, 29% and 57%, respectively. Multivariate analysis of cross-sectional data showed that gender, age, and serum uric acid (UA) were major factors which consistently affected eGFR at both baseline and follow-up, and that higher systolic blood pressure (SBP) and presence of plaque were involved in lower eGFR at the follow-up point. In longitudinal analysis, five baseline factors - age, SBP, low-density lipoprotein cholesterol (LDL-C), serum transferrin (TRF) and eGFR - independently predicted a greater variability in renal function. In addition, presence of plaque was an independent risk factor for a faster decline of eGFR. CONCLUSIONS: Cross-sectional analysis demonstrates that renal function declines with increasing age. However, 43% of participants did not experience a decline in eGFR during follow-up. Besides older age and higher initial eGFR, presence of atherosclerotic carotid plaque, higher SBP, higher LDL-C and lower TRF are independent risk factors to predict a rapid decline of renal function in the healthy Chinese population.

Effects of decline in renal function with age on the outcome of asymptomatic carotid plaque in healthy adults: a 5-year follow-up study.

BACKGROUND: It has been long suggested that abnormal clinical factors in the body, such as dyslipidemia and diabetes, can affect the presence of atherosclerosis. However, few studies on the effect of factors within the normal range, such as the loss of renal function with age, on the prevalence of atherosclerosis are few know in healthy individuals. The aim of this study was to investigate risk factors affecting the presence of asymptomatic carotid plaques in a middle-aged and elderly healthy population. METHODS: In this regard, we prospectively evaluated 245 healthy individuals (98 males and 147 females) at baseline and after 5 years. Changes in the presence of carotid plaque between 2003 and 2008 were categorized into four groups, i.e. subjects without plaque at entry (n = 165): Group 1 (without plaque on two occasions, n = 129) and Group 2 (with nascent plaque at follow-up, n = 36); subjects with plaque at entry (n = 80); Group 3 (with plaque regression at follow-up, n = 29) and Group 4 (with plaque on two occasions, n = 51). RESULTS: Univariate analysis showed that the positive rate of carotid plaques in males was higher than that in females at the baseline, and that a significantly inverse correlation existed between the prevalence rate of plaque and aging. Logistic regression analysis of cross-sectional research showed that independent risk factors for the prevalence of atherosclerosis were male gender, lower estimated glomerular filtration rate (eGFR) and higher low-density lipoprotein cholesterol (LDL-C) at the baseline, and older age and lower eGFR were involved in the presence of carotid plaques at follow-up point. However, logistic regression analysis of the longitudinal data showed that older age, decreased eGFR and increased systolic blood pressure (SBP) independently predicted the presence of carotid plaques after 5 years in subjects without plaque at entry. In addition, in subjects with plaque at entry, age, changes in eGFR and the baseline levels of serum albumin (ALB) and serum total bilirubin (BIL) dependently influenced the outcome of carotid plaque. CONCLUSION: Physiological decline of renal function, together with advancing age, was an independent risk factor which consistently affected the presence of carotid atherosclerosis in two categories of healthy individuals.

Progesterone levels and carotid intima-media thickness: a negative association in older northern Chinese men.

In experimental research, progesterone has been found to be beneficial to the central nervous and cardiovascular systems; however, its potential role in preventing atherosclerosis in elderly men remains unclear. In this prospective study, we analyzed data in 385 older men and women from 6 communities in Beijing, China, in order to discover whether progesterone is associated with carotid intima-media thickness and plaque occurrence. Intima-media thickness and atherosclerotic plaques were determined by use of ultrasonography. Sex-hormone levels were measured by immunoassay. The data were analyzed via analysis of covariance and logistic regression analysis; P < 0.05 was considered statistically significant. We found a negative association between mean intima-media thickness and progesterone concentration in men, before and after adjustments for such traditional risk factors of atherosclerosis as age, triglyceride levels, total and low-density lipoprotein cholesterol levels, high-sensitivity C-reactive protein, systolic blood pressure, waist-to-hip ratio, and body mass index (analysis of covariance, P = 0.007 and P = 0.015, respectively). However, no such association was found in women (P = 0.304 and P = 0.247, respectively). In the logistic regression model that was adjusted for the confounding factors of atherosclerosis, men with progesterone levels in the lowest quartile (<1.87 nmol/L) had more risk of higher intima-media thickness (odds ratio, 2.15; P = 0.042). Although further experimental and prospective studies are warranted in order to determine the mechanism of progesterone's function in atherosclerosis prevention, we conclude that progesterone concentrations are negatively associated with carotid artery atherosclerosis in northern Chinese men 60 years of age or older.