Publications by authors named "Ying-Chun Ma"

19 Publications

  • Page 1 of 1

Cognitive impairment and associated risk factors in older adult hemodialysis patients: a cross-sectional survey.

Sci Rep 2020 07 27;10(1):12542. Epub 2020 Jul 27.

Department of Nephrology, Chinese PLA General Hospital, State Key Laboratory of Kidney Disease, Beijing, 100853, China.

The clinical epidemiological features of cognitive impairment in Chinese older adult patients undergoing hemodialysis are not clear, we aimed to identify the extent and patterns of cognitive impairment among those patients. We conducted a cross-sectional study of 613 hemodialysis patients aged 50 to 80 from 11 centers in Beijing. A neuropsychological battery of 11 tests covering domains of attention/processing speed, executive function, memory, language, and visuospatial function was applied, patients were classified as none, mild, or major cognitive impairment according to the fifth version of the Diagnostic and Statistical Manual of Mental Disorders criteria for cognitive impairment. Compared with Chinese population norms, 37.2% of the participants had mild cognitive impairment, 43.7% had major cognitive impairment. Memory and language were the most severe impaired domains in the mild cognitive impairment group, attention and visuospatial function domains were the most serious impaired domains in the major cognitive impairment group. Concomitant impairment across multiple cognitive domains was common. Factors associated with major cognitive impairment included age, education level, history of stroke and hypertension, dialysis vintage, and single-pool Kt/V. There is a high frequency of cognitive impairment in Chinese older adult hemodialysis patients, with varying severity and concomitant impairment across multiple domains.
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http://dx.doi.org/10.1038/s41598-020-69482-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7385128PMC
July 2020

Effect of Intradialytic Exercise on Physical Performance and Cardiovascular Risk Factors in Patients Receiving Maintenance Hemodialysis: A Pilot and Feasibility Study.

Blood Purif 2020 19;49(4):409-418. Epub 2019 Dec 19.

Department of Nephrology, Peking University People's Hospital, Beijing, China.

Introduction: Although intradialytic exercise is considered a form of "nonpharmacological medicine" for patients receiving maintenance hemodialysis (MHD), this practice has not been widely implemented in most dialysis centers because of clinical limitations. We, therefore, aimed to design an intradialytic exercise training program to improve the implementation of this practice and determine its impact on physical performance and cardiovascular risk factors in patients receiving MHD.

Methods: A total of 132 MHD patients at 4 outpatient dialysis units were enrolled and assigned randomly into exercise (n = 67) and control groups (n = 65). During a 2-year period, patients in the exercise group participated in 20-min exercise training sessions within dialysis sessions on 3 days per week. All patients underwent assessments of physical function (6-min walk test) and cardiovascular risk factors (blood pressure [BP], total cholesterol [TC], low-density lipoprotein [LDL], high-sensitivity C-reactive protein [hsCRP], albumin [Alb], hemoglobin [Hb], and erythropoietin [EPO] dose) at the baseline and annually thereafter.

Results: Of the participants, 50.8% had completed the study after 2 years. No statistically significant intragroup or intergroup differences were observed in the measures of 6MD, BP, TC, hsCRP, Alb, Hb, and EPO dose.

Conclusion: The results suggest that although this low-intensity, nonprogressive intradialytic exercise program may be practical, it was not sufficient to improve physiological function and reduce cardiovascular disease risk factors in patients receiving MHD.
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http://dx.doi.org/10.1159/000504955DOI Listing
May 2021

Motivators for and Barriers to Exercise Rehabilitation in Hemodialysis Centers: A Multicenter Cross-Sectional Survey.

Am J Phys Med Rehabil 2020 05;99(5):424-429

From the Department of Nephrology, China Rehabilitation Research Center, Beijing BoAi Hospital, Capital Medical University Rehabilitation Medical College, Beijing, China (X-XW, Z-HL, Y-CM); Department of Nephrology, Peking University People's Hospital, Beijing, China (YW); Hemodialysis Center, Beijing Zhan Lan Lu Hospital, Beijing, China (M-CX); Hemodialysis Center, General Hospital of China Aviation of Beijing, Beijing, China (Z-MK); and Hemodialysis Center, Chui Yang Liu Hospital affiliated to Tsinghua University, Beijing, China (WZ).

Objectives: The aim of the study was to explore motivators for and barriers to exercise rehabilitation in hemodialysis patients and the barriers perceived by the hemodialysis center staff.

Design: A cross-sectional study was performed in five hemodialysis centers using patient questionnaires designed for this study to evaluate the motivators for and barriers to exercise rehabilitation. Questionnaires were not yet validated.

Results: Of the 471 recruited patients, 63.3% were willing to participant in exercise rehabilitation. The greatest motivators included improving quality of life (98.0%) and wanting to be healthier (98.0%). Perceived barriers included discomfort (59.0%), concerns regarding safety (36.7%), and disinterest (27.0%). Among these, unwillingness, disinterest, and having peripheral arterial disease were independent risk factors of lack of participation in exercise rehabilitation. The most common perceived barriers among the 90 employees that participated were lack of professional guidance and advice from rehabilitation therapists (93.1%), lack of exercise rehabilitation knowledge (86.2%), and lack of special exercise equipment (86.2%).

Conclusions: Most patients were willing to exercise to improve their health and quality of life. Barriers to exercise rehabilitation included patient and staff factors. It is essential to establish a rehabilitation team within dialysis centers, including general staff and rehabilitation therapists. These centers require improved rehabilitation policies and access to specialized rehabilitation equipment.
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http://dx.doi.org/10.1097/PHM.0000000000001360DOI Listing
May 2020

Serum Homocysteine as a Prognostic Biomarker for Short-Term Mortality in HBV-Related Acute-on-Chronic Liver Failure Patients.

Clin Lab 2018 May;64(5):727-733

Background: The liver plays a central role in the synthesis and metabolism of homocysteine (Hcy). The present study aimed to determine the prognostic role of serum Hcy levels in patients with HBV-related acute-on-chronic liver failure (AoCLF).

Methods: Fifty-two AoCLF and 52 chronic hepatitis B (CHB) patients were recruited. The virological parameters and biochemical examination of blood were obtained after 12 hours of fasting. In the AoCLF group, the relationships between the prognosis and the Hcy level were analyzed. The primary end-point was 3-month in-hospital mortality.

Results: A significantly higher Hcy level was detected in AoCLF patients than in the healthy controls (HCs) and CHB groups (both p < 0.01). The Hcy level was positively correlated with the model of end-stage liver disease (MELD) score and the creatinine levels and was inversely correlated with the estimated glomerular filtration rate. Moreover, Hcy levels at presentation were higher among non-survivors than survivors in AoCLF patients. Multivariate analysis suggested that both Hcy level and MELD score were independent predictors of 3-month mortality in patients with AoCLF (p < 0.001).

Conclusions: Serum Hcy level measured at admission may serve as a biomarker for 3-month mortality rate in patients with HBV-AoCLF.
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http://dx.doi.org/10.7754/Clin.Lab.2018.171105DOI Listing
May 2018

[The effects of ERK1/2 pathway on the expression of calcium activated chloride channel in hypoxia in PASMCs rat model].

Zhongguo Ying Yong Sheng Li Xue Za Zhi 2017 Jan;33(1):47-50

Department of Pathophysiology, Wenzhou Medical University, Wenzhou 325035.

Objective: To investigate the expression of mRNA and protein of Calcium activated chloride channel (CLCA2) in hypoxic pulmonary artery smooth muscle cell (PASMCs) of rat and it's relationship with ERK1/2 signal pathway.

Methods: PASMCs were randomly divided into 5 groups including normal group(N group), hypoxia group(H group), DMSO group(D group), U0126 group (U group) and Staurosporine aglycone group(SA group). The protein expression of CLCA2 in PASMCs was detected by Western blot.The mRNA expression of CLCA2 was detected by half quantitative reverse transcription polymerase chain reaction (RT-PCR).

Results: The mRNA and protein expressions of CLCA2 in H group were significantly higher than N group (<0.01). Comparing with D group,the mRNA and protein expressions of CLCA2 were significantly increased in U group (<0.01),the mRNA expression of CLCA2 in SA group was obviously decreased (<0.01) with slightly decreasing of its protein expression.

Conclusions: Hypoxia promotes the expressions of mRNA and protein of CLCA2 in rat PASMCs. The ERK1/2 pathway activator Staurosporine aglycone reduces the mRNA and protein expression of CLCA2 in rats PASMCs and the ERK1/2 pathway inhibitor U0126 induces the upregulation of the mRNA and protein expressiosn of CLCA2 in rats PASMCs.
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http://dx.doi.org/10.12047/j.cjap.5448.2017.011DOI Listing
January 2017

[Ischemic postconditioning attenuates pneumocyte apoptosis after lung ischemia/reperfusion injury via inactivation of p38 MAPK].

Zhongguo Ying Yong Sheng Li Xue Za Zhi 2014 May;30(3):251-6

Objective: To investigate the role of p38 MAPK on ischemic postconditioning (IPO) attenuating pneumocyte apoptosis after lung ischemia/reperfusion injury (LIRI).

Methods: Forty adult male SD rats were randomly divided into 5 groups based upon the intervention (n = 8): control group (C), LIR group (I/R), LIR + IPO group (IPO), IPO + solution control group (D), IPO + SB203580 group (SB). Left lung tissue was isolated after the 2 hours of reperfusion, the ratio of wet lung weight to dry lung weight (W/D), and total lung water content (TLW) were measured. The histological structure of the left lung was observed under light and electron transmission microscopes, and scored by alveolar damage index of quantitative assessment (IQA). Apoptosis index (AI) of lung tissue was determined by terminal deoxynuleotidyl transferase mediated dUTP nick end and labeling (TUNEL) method. The mRNA expression and protein levels of and Bax were measured by RT-PCR and quantitative immunohistochemistry (IHC).

Results: Compared with C group, W/D, TLW, IQA, AI and the expression of Bax of I/R were significantly increased, the expression of Bcl-2 and Bcl-2/Bax were significantly decreased (P < 0.05, P < 0.01), and was obviously morphological abnormality in lung tissue. Compared with I/R group, all the indexes of IPO except for the expression of Bcl-2 and Bcl-2/ Bax were obviously reduced, the expression of Bcl-2 and Bcl-2/Bax were increased (P < 0.05, P < 0.01). All the indexes between D and IPO were little or not significant( P > 0.05). The expression of Bcl-2 and Bcl-2/Bax of SB were significantly increased and other indexes were reduced than those of IPO (P < 0.05, P < 0.01).

Conclusion: IPO may attenuate pneumocyte apoptosis in LIRI by inactivation of p38 MAPK, up-regulating expression of Bcl-2/Bax ratio.
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May 2014

[Glybenclamide regulate ERK1/2 signal pathway during hypoxia hypercapnia pulmonary vasoconstriction in rats].

Zhongguo Ying Yong Sheng Li Xue Za Zhi 2014 Mar;30(2):110-4

Objective: To investigate the role and significance of ATP-sensitive K+ channels in the pathological process of hypoxia hypercapnia-induced pulmonary vasoconstriction (HHPV) and the relationship with ERK1/2 signal pathway in rats.

Methods: We made the third pulmonary artery rings of SD rats, used the model of pulmonary artery rings perfusion in vitro. Under acute hypoxia hypercapnia condition, and observed the effects of the three stages of HHPV incubated by glybenclamide(Gly) and the combined application of Gly and U0126. At the same time, the values of rings' tension changes were recorded via the method of hypoxia hypercapnia conditions reactivity.

Results: Under the normoxia condition, the values of the third pulmonary artery rings tension were relatively stable, but under the hypoxia hypercapnia condition, we observed a biphasic pulmonary artery contractile response compared with N group (P < 0.05, P < 0.01). When the third pulmonary artery rings incubated by Gly, it's phase II persistent vasoconstriction was enhanced compared with the H group (P < 0.05, P < 0.01), and the phase I vasoconstriction was also heightened. Moreover, under the hypoxia hypercapnia condition, U0126 could significantly relieve the phase II persistent vasoconstriction compared with HD group (P < 0.05, P < 0.01) induced by Gly, but the phase I acute vasoconstriction and the phase I vasodilation had no changes (P > 0.05).

Conclusion: Gly may mediate HHPV via activating ERK1/2 signal transduction pathway.
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March 2014

[Expression of KATP in pulmonary artery smooth muscle cells under hypoxia-hypercapnia condition and the relationship with p38 MAPK pathway].

Sheng Li Xue Bao 2014 Jun;66(3):283-8

Department of Pathophysiology; Institute of Ischemia/Reperfusion Injury, Wenzhou Medical University, Wenzhou 325035, China; Department of Pathology, Tongde Hospital of Zhejiang Province, Hangzhou 310012, China.

The aim of the present study is to investigate the expressions of ATP-sensitive K(+) channels (KATP) in pulmonary artery smooth muscle cells (PASMCs) and the relationship with p38 MAPK signal pathway in rats. Male SD rat PASMCs were cultured in vitro, and a model of hypoxia and hypercapnia was reconstructed. PASMCs were divided to normal (N), hypoxia-hypercapnia (H), hypoxia-hypercapnia+DMSO incubation (HD), hypoxia-hypercapnia+SB203580 (inhibitor of p38 MAPK pathway) incubation (HS) and hypoxia-hypercapnia+Anisomycin (agonist of p38 MAPK pathway) incubation (HA) groups. Western blot was used to detect the protein expression of SUR2B and Kir6.1; semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of SUR2B and Kir6.1. The results demonstrated that: (1) Compared with N, H, HD and HS groups, the expressions of Kir6.1 mRNA and protein in PASMCs of HA group were decreased significantly (P < 0.01), but there were no differences among N, H, HD and HS groups (P > 0.05); (2) Compared with N group, the expressions of SUR2B mRNA and protein in H, HD, HS and HA groups were increased significantly (P < 0.05), but there were no differences among H, HD, HS and HA groups (P > 0.05). The results imply that: (1) Hypoxia-hypercapnia, SB203580 didn't change the expressions of Kir6.1 mRNA and protein in PASMCs, but Anisomycin decreased the expressions of Kir6.1 mRNA and protein, so Kir6.1 may be regulated by the other subfamily of MAPK pathway; (2) Hypoxia-hypercapnia raised SUR2B mRNA and protein expressions in PASMCs, but SB203580 and Anisomycin did not affect the changes, so the increasing of SUR2B mRNA and protein induced by hypoxia-hypercapnia may be not depend on p38 MAPK pathway.
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June 2014

[Calcium-activated chloride channels are involved in two-phase hypoxic pulmonary vasoconstriction in rat pulmonary arteries].

Sheng Li Xue Bao 2014 Apr;66(2):203-9

Department of Pathophysiology; Institute of Ischemia-reperfusion Injury, Wenzhou Medical University, Wenzhou 325035, China; Department of Anesthesiology, The Sixth People's Hospital of Shanghai, Shanghai 200233, China.

The aim of the present study was to investigate the roles of calcium-activated chloride channels (Cl(Ca)) in the two-phase hypoxic pulmonary vasoconstriction (HPV). The second pulmonary artery branches were dissected from male Sprague-Dawley rats, and the changes in vascular tone were measured by using routine blood vascular perfusion in vitro. The result showed that, under normoxic conditions, Cl(Ca) inhibitors (NFA and IAA-94) significantly relaxed second pulmonary artery contracted by norepinephrine (P < 0.01), but merely had effects on KCl-induced second pulmonary artery contractions. A biphasic contraction response was induced in second pulmonary artery ring pre-contracted with norepinephrine exposed to hypoxic conditions for at least one hour, but no biphasic contraction was observed in pulmonary rings pre-contracted with KCl. NFA and IAA-94 significantly attenuated phase II sustained hypoxic contraction (P < 0.01), and also attenuated phase I vasodilation, but had little effect on phase I contraction. These results suggest that Cl(Ca) is an important component forming phase II contraction in secondary pulmonary artery, but not involved in phase I contraction.
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April 2014

[The effect of niflumic acid in hypoxic hypercapnia pulmonary vasoconstriction].

Zhongguo Ying Yong Sheng Li Xue Za Zhi 2014 Jan;30(1):74-8

Objective: To investigate the effect of chloride channel blocker--niflumic acid (NFA) on the pathological process of hypoxia hypercapnia-induced pulmonary vasoconstriction in rats.

Methods: We used the model of hypoxia hypercapnia-induced pulmonary vasoconstriction rats, and divided the second, third branch pulmonary artery rings randomly into four groups (n = 8): control group (N group), hypoxia hypercapnia group (H group), DMSO incubation group (HD group), niflumic acid group (NFA group). Under acute hypoxia hypercapnia conditions, we observed the effects of the three stages of hypoxia hypercapnia-induced pulmonary vasoconstriction (HHPV) incubated by NFA in the second, third brach pulmonary artery rings. At the same time, the values of rings' tension changings were recorded via the method of hypoxia hypercapnia conditions reactivity. And investigated the effect of NFA to HHPV.

Results: (1) Under the hypoxia hypercapnia condition, we observed a biphasic pulmonary artery contractile (the phase I rapid contraction and vasodilation; the phase II sustained contraction) response in both the second and the third branch pulmonary artery rings compared with the control group (P < 0.05 , P < 0.01); (2) The second and third pulmonary artery rings incubated by NFA which phase II persistent vasoconstriction were significantly attenuated compared with the H group (P < 0.05 , P < 0.01).

Conclusion: The blocker of the chloride channels attenuates the second and third branch pulmonary artery rings constriction in rat, especially the phase II persistent vasoconstriction, so then have an antagonistic effect on HHPV.
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January 2014

[Effects of ischemic postconditioning on pneumocyte apoptosis after lung ischemia/reperfusion injury in rats].

Zhongguo Ying Yong Sheng Li Xue Za Zhi 2014 Jan;30(1):60-3

Objective: To investigate the effects of ischemic postconditioning (IPostC) on pneumocyte apoptosis after lung ischemia/reperfusion injury in rats.

Methods: Adult male SD rats were randomly divided into 3 groups based upon the intervention (n = 8): control group (C), lung ischemic reperfusion group (LIR), LIR+ IPostC group (IPostC). At the end of the experiment, blood specimens drawn from the arteria carotis were tested for the content of malondialdehyde (MDA), the activity of superoxide dismutase (SOD) and myeloperoxidase (MPO); the pneumocyte apoptosis index (AI) was achieved by tennrminal deoxynucleotidyl transferase mediated dUTP nick end abeling (TUNEL); the expression of Bcl-2, Bax protein in lung tissue was accessed by quantitative immunohistochemistry (MHC) and Bcl-2, Bax mRNA by RT-PCR.

Results: IPostC could significantly attenuate the MDA level, MPO activity and improve SOD activity in blood serum which was comparable to I/R and significantly reduced the number of TUNEL-positive cells compared with I/R group, expressed as Al (% total nuclei) from (39.0 +/- 3.46) to (8.0 +/- 0.88) (P < 0.01). The protein and mRNA expression of Bcl-2 and Bax showed that IPO significantly attenuated the ischemia/reperfusion-upregulated expression of Bax protein but improved the expression of Bcl-2 that improved the Bcl-2/Bax ratio (P < 0.01) .

Conclusion: IPostC may attenuate pneumocyte apoptosis in LIRI by up-regulating expression of Bcl-2/Bax ratio and by inhibiting oxidant generation and neutrophils filtration.
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January 2014

Aberrant methylation of RASSF2A in tumors and plasma of patients with epithelial ovarian cancer.

Asian Pac J Cancer Prev 2014 ;15(3):1171-6

Department of Gynecology and Obstetrics, Qilu Hospital, Shandong University, Jinan, China E-mail :

Objective: The tumor suppressor gene, Ras-association domain family (RASSF)2A, is inactivated by promoter hypermethylation in many cancers. The current study was performed to evaluate the methylation status of RASSF2A in epithelial ovarian cancer (EOC) tissues and plasma, and correlations with gene expression and clinicopathologic characteristics.

Method: We detected methylation of the RASSF2A gene in tissues and corresponding plasma samples from 47 EOC patients and 14 patients with benign ovarian tumors and 10 with normal ovarian tissues. The methylation status was determined by methylation-specific PCR while gene expression of mRNA was examined by RT-PCR. The EOC cell line, SKOV3, was treated with 5-aza-2'-deoxycytidine (5-aza- dC).

Results: RASSF2A mRNA expression was significantly low in EOC tissues. The frequency of aberrant methylation of RASSF2A was 51.1% in EOC tissues and 36.2% in corresponding plasma samples, whereas such hypermethylation was not detected in the benign ovarial tumors and normal ovarian samples. The expression of RASSF2A mRNA was significantly down-regulated or lost in the methylated group compared to the unmethylated group (p<0.05). After treatment with 5-aza-dC, RASSF2A mRNA expression was significantly restored in the Skov3 cell line.

Conclusion: Epigenetic inactivation of RASSF2A through aberrant promoter methylation may play an important role in the pathogenesis of EOC. Methylation of the RASSF2A gene in plasma may be a valuable molecular marker for the early detection of EOC.
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http://dx.doi.org/10.7314/apjcp.2014.15.3.1171DOI Listing
November 2014

Development of formulae for accurate measurement of the glomerular filtration rate by renal dynamic imaging.

Nucl Med Commun 2007 May;28(5):407-13

Department of Nuclear Medicine, Peking University First Hospital, Beijing, China.

Aim: Currently, the widely adopted renal dynamic imaging in clinical practice uses Gates' method to calculate the glomerular filtration rate (GFR), but many researchers have proven that Gates' method may result in bias. Thus, this article explores alternative improved formulae to calculate GFR by renal dynamic imaging.

Methods: Three hundred and sixty-seven patients were selected and their GFR values were measured using renal dynamic imaging and the two-plasma method with 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) as the imaging agent. With the two-plasma GFR as reference value, two equations were obtained from linear and non-linear regression analyses between the renal uptake percentage and two-plasma GFR. The 367 patients were divided into two random groups, with the first group used to derive the regression formulae and the second to verify the formulae. Finally, all patients were studied to derive the formulae to calculate GFR. The comparison of our formulae with the commonly used Gates' formula was conducted by the Bland-Altman method.

Results: The linear and non-linear GFR formulae were as follows: GFR (ml/min/1.73 m2)=(631.633 x renal uptake percentage - 2.040) x 1.73/BSA (BSA, body surface area) and GFR (ml/min/1.73 m2)=(-1996.585 x renal uptake percentage2 + 1013.526 x renal uptake percentage - 12.739) x 1.73/BSA, respectively. The biases of the GFR values calculated using the linear and non-linear formulae and Gates' formula relative to the two-plasma GFR were -2.5 +/- 19.1 ml/min/1.73 m2, -2.0 +/- 19.3 ml/min/1.73 m2 and 3.4 +/- 19.4 ml/min/1.73 m2, respectively.

Conclusions: The GFR values calculated using our new formulae correlate better with the reference GFR value than does GFR calculated by Gates' formula, and the GFR values measured using the non-linear formula are more accurate than those obtained using the linear formula.
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http://dx.doi.org/10.1097/MNM.0b013e3280a02f8bDOI Listing
May 2007

Comparison of 99mTc-DTPA renal dynamic imaging with modified MDRD equation for glomerular filtration rate estimation in Chinese patients in different stages of chronic kidney disease.

Nephrol Dial Transplant 2007 Feb 19;22(2):417-23. Epub 2006 Oct 19.

Institute of Nephrology and Division of Nephrology, First Hospital, Peking University, No. 8 Xishiku Street, Xicheng District, Beijing 100034, P.R. China.

Background: The renal dynamic imaging method (modified Gate's method) with (99m)Tc-diethylene triamine pentaacetic acid ((99m)Tc-DTPA) is simple and less time consuming for glomerular filtration rate (GFR) estimation than other methods. However, its diagnostic performance as a surrogate marker of GFR is questioned increasingly. Recently, the modified Modification of Diet in Renal Disease (MDRD) study equation based on data from Chinese patients of chronic kidney disease (CKD) showed significant performance improvement. In the present study, the renal dynamic imaging methods and the modified abbreviated MDRD equation were compared with the plasma clearance method.

Methods: Four hundred and eighty two patients with CKD were selected. GFR were estimated simultaneously using three methods: (i) modified Gate's method (gGFR); (ii) the modified abbreviated MDRD equation (c-aGFR) and (iii) dual plasma sampling method (rGFR). Using rGFR as the reference method, gGFR and c-aGFR were compared with rGFR in each stage of CKD.

Results: Both gGFR and c-aGFR were correlated well with rGFR (r(gGFR) = 0.81 and r(c-aGFR) = 0.90, P < 0.001). In the overall performance, c-aGFR had less bias (849.5 vs 933.1 arbitrary units), higher precision (57 vs 78.4 ml/min/1.73 m(2)) and higher accuracy than gGFR. For gGFR, the 15, 30 and 50% accuracies were 32.4, 56.0 and 79.1%, respectively; for c-aGFR, the corresponding accuracy rose to 43.2%, 75.5% and 90.9%, respectively. In each stage of CKD, the modified abbreviated MDRD equation also outperformed the modified Gate's method in the GFR estimation.

Conclusion: Our results indicated that the performance of the renal dynamic imaging in total GFR estimation was not better than the modified abbreviated MDRD equation in our patient group, and should not be used as a surrogate marker of GFR, especially in clinical trials. We presume that the dynamic renal imaging methods for estimation of GFR can be improved by using proper reference GFR, more adequate background subtraction and soft-tissue attenuation correction, in a relatively larger sample size.
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http://dx.doi.org/10.1093/ndt/gfl603DOI Listing
February 2007

Modified glomerular filtration rate estimating equation for Chinese patients with chronic kidney disease.

J Am Soc Nephrol 2006 Oct 20;17(10):2937-44. Epub 2006 Sep 20.

Division of Nephrology and Institute of Nephrology, The First Hospital, Peking University, No. 8 Xishiku Street, Xicheng District, Beijing 100034, PR China.

The Modification of Diet in Renal Disease (MDRD) equations provide a rapid method of assessing GFR in patients with chronic kidney disease (CKD). However, previous research indicated that modification of these equations is necessary for application in Chinese patients with CKD. The objective of this study was to modify MDRD equations on the basis of the data from the Chinese CKD population and compare the diagnostic performance of the modified MDRD equations with that of the original MDRD equations across CKD stages in a multicenter, cross-sectional study of GFR estimation from plasma creatinine, demographic data, and clinical characteristics. A total of 684 adult patients with CKD, from nine geographic regions of China were selected. A random sample of 454 of these patients were included in the training sample set, and the remaining 230 patients were included in the testing sample set. With the use of the dual plasma sampling (99m)Tc-DTPA plasma clearance method as a reference for GFR measurement, the original MDRD equations were modified by two methods: First, by adding a racial factor for Chinese in the original MDRD equations, and, second, by applying multiple linear regression to the training sample and modifying the coefficient that is associated with each variable in the original MDRD equations and then validating in the testing sample and comparing it with the original MDRD equations. All modified MDRD equations showed significant performance improvement in bias, precision, and accuracy compared with the original MDRD equations, and the percentage of estimated GFR that did not deviate >30% from the reference GFR was >75%. The modified MDRD equations that were based on the Chinese patients with CKD offered significant advantages in different CKD stages and could be applied in clinical practice, at least in Chinese patients with CKD.
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http://dx.doi.org/10.1681/ASN.2006040368DOI Listing
October 2006

[Comparison of single plasma sample methods and prediction of dual plasma sample method in measurement of 99mTc-Diethylene Triamine Pentaacetic Acid plasma clearance].

Beijing Da Xue Xue Bao Yi Xue Ban 2005 Dec;37(6):633-7

Peking University First Hospital, Institute of Nephrology, Beijing 100034, China.

Objective: To find an applicable condition of the single-plasma-sample method (SPSM) to measure the glomerular filtration(GFR) with (99m)Tcj Diethylene Triamine Pentaacetic Acid ((99m)Tc-DTPA), and predict the value of (99m)Tc-DTPA plasma clearance by dual plasma sample method (DPSM ) from that by SPSM.

Methods: Three hundred and thirty five patients with chronic kidney disease (CKD) were selected (192 males and 143 females). The average age was 51.91+/-14.76 years. The GFR was determined simultaneously by 2 methods: (1) SPSM (sGFR); (2) DPSM (tGFR), using DPSM as reference standard, sGFR calculated from the different SPSM was compared with tGFR. An equation was developed to predict tGFR from sGFR. GFR estimated by abbreviated Modification of Diet in Renal Disease (MDRD) equation (aGFR) was evaluated as the criterion in selection of DPSM and SPSM. The condition that DPSM could be substituted by SPSM in GFR measurement was given.

Results: When tGFR >or= 30 mL/(minx1.73 m(2)), all of the sGFR were significantly correlated with tGFR. Among them, Watson modified Christensen and Groth's equation at sample time=240 min tended to be the most accurate (r=0.977, RMSE=10.91), and tGFR could be predicted from sGFR using the equation: Predicted tGFR [mL/(minx1.73 m(2))]=7.755 4+0.789 3xsGFR+0.002 4 xsGFR2 (n=297, r2=0.959 1, P<0.001). When aGFR was less than 50 mL/(minx1.73 m(2)), the diagnostic sensitivity of tGFR<30 mL/(minx1.73 m(2)) was 94.7%, and recommended as the criterion in selection of DPSM and SPSM.

Conclusion: When aGFR >or=50 mL/(minx1.73 m(2)), DPSM can be substituted by SPSM in GFR measurement.
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December 2005

[The application of glomerular filtration rate estimation equations in different stages of chronic kidney disease].

Zhonghua Nei Ke Za Zhi 2005 Apr;44(4):285-9

Institute of Nephrology and Division of Nephrology, the First Hospital, Peking University, Beijing 100034, China.

Objective: To understand the applicability of MDRD equation in Chinese patients with chronic kidney disease (CKD). Glomerular filtration rate (GFR) estimated with MDRD equation, abbreviated MDRD equation and Cockcroft-Gault equation was compared with (99m)Tc-DTPA plasma clearance by dual plasma sampling method in different stages of CKD.

Methods: CKD were diagnosed according to K/DOQI guideline.298 patients with CKD were selected. Patients'sex, age, height and body weight were recorded and plasma creatinine, urea nitrogen and albumin were measured in a single clinical laboratory. (99m)Tc-DTPA plasma clearance was calculated and standardized by body surface area (sGFR). GFRs estimated with MDRD equation 7, abbreviated MDRD equation and Cockcroft-Gault equation (7GFR, aGFR and cGFR) were compared with sGFR in different stages of CKD.

Results: There were 165 male and 133 female in the selected 298 patients with CKD;the average age was (52.5 +/- 15.5) years. There was significant difference between the GFRs of the 3 equations with sGFR in different stages of CKD (P < 0.001). 7GFR, aGFR and cGFR were significantly higher than sGFR in CKD stages 5-4; the lower the sGFR, the more the differences. 7GFR, aGFR and cGFR were significantly lower than sGFR in CKD stage 2-1; the higher the sGFR, the more the differences.

Conclusion: Our results showed that in Chinese population with CKD, MDRD equation 7, abbreviated MDRD equation and Cockcroft-Gault equation overestimate actual GFR in CKD stages 4-5 and underestimate GFR in CKD stages 1-2. These results indicate that MDRD equation and its modifications for estimation of GFR should be amended when applying to Chinese patients with CKD in clinical practice.
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April 2005

Application of GFR-estimating equations in Chinese patients with chronic kidney disease.

Am J Kidney Dis 2005 Mar;45(3):463-72

Institute of Nephrology and Division of Nephrology, First Hospital, Peking University, Beijing, PR China.

Background: To evaluate whether the Modification of Diet in Renal Disease (MDRD) equations could be applied accurately to Chinese patients with chronic kidney disease (CKD), glomerular filtration rates (GFRs) estimated by using MDRD equation 7 (7GFR), the abbreviated MDRD equation (aGFR), and the Cockcroft-Gault equation (cGFR) were compared in patients with different stages of CKD.

Methods: The study enrolled patients with CKD diagnosed according to the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative guidelines. All patients were older than 18 years and without acute renal function deterioration, edema, skeletal muscle atrophy, or amputation. Sex, age, body height, and body weight were recorded, and plasma creatinine levels were measured by means of Jaffe's kinetic method using a Hitachi 7600 analyzer (Hitachi, Tokyo, Japan; reagents from Roche Diagnostics, Mannheim, Germany). Creatinine, urea, and albumin were measured in a single clinical laboratory. Dual plasma sampling of technetium Tc 99m-labeled diethylene triamine pentaacetic acid plasma clearance was used as the reference standard GFR (sGFR) for comparison of 7GFRs, aGFRs, and cGFRs at different stages of CKD.

Results: The study enrolled 261 patients, including 146 men and 115 women. Causes of CKD included primary or secondary glomerular disease, obstructive kidney disease, chronic tubulointerstitial disease, and others. Values for 7GFR, aGFR, and cGFR were significantly greater than for sGFR in patients with CKD stages 4 to 5 (the lower the sGFR, the greater the difference); whereas 7GFR, aGFR, and cGFR were significantly lower than sGFR in patients with CKD stage 1.

Conclusion: Our results show that in a Chinese population with CKD, MDRD equation 7 and the abbreviated MDRD equation overestimated GFR in patients with CKD stages 4 to 5 and underestimated GFR in those with CKD stage 1. These results indicate that careful modification of these equations may be necessary in Chinese populations with CKD.
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http://dx.doi.org/10.1053/j.ajkd.2004.11.012DOI Listing
March 2005
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