Validation of the EKFC equation for glomerular filtration rate estimation and comparison with the Asian-modified CKD-EPI equation in Chinese chronic kidney disease patients in an external study.

OBJECTIVES: The aim of this study is to determine whether new European Kidney Function Consortium (EKFC) equation is more applicable than Asian-modified CKD-EPI equation in clinical practice, having a higher accuracy in estimating GFR in our external CKD population. METHODS: We calculated estimated GFREKFC and GFRCKD-EPI independently using the EKFC and Asian-modified CKD-EPI formulas, respectively. The clinical diagnostic performance of the two equations was assessed and compared by median bias, precision, accuracy (P30) and so on, using 99mTc-DTPA dual plasma sample clearance method as a reference method for GFR measurement (mGFR). The equation that met the following targets was superior: (1) median bias within ± 3 mL/min/1.73 m2; (2) P30 > 75%; and (3) better precision and 95% limits of agreement in Bland-Altman analysis. RESULTS: Totally, 160 CKD patients were recruited in our external cohort. GFREKFC was highly related to mGFR, with a regression equation of GFREKFC=mGFR × 0.87 + 5.27. Compared with the Asian-modified CKD-EPI equation, EKFC equation demonstrated a wider median bias (-1.64 vs. 0.84 mL/min/1.73 m2, p < 0.01) that was within 3 mL/min/1.73 m2 and not clinically meaningful. Furthermore, the precision (12.69 vs. 12.72 mL/min/1.73 m2, p = 0.42), 95% limits of agreement in Bland-Altman analysis (42.4 vs. 44.4 mL/min/1.73 m2) and incorrect reclassification index of the two target equations were almost identical. Although, EKFC equation had a slightly better P30 (80.0% vs. 74.4%, p = 0.01). CONCLUSIONS: The overall performance of EKFC equation is acceptable. There is no clinically meaningful difference in the performance of the Asian-modified CKD-EPI and EKFC equations within the limits imposed by the small sample size.

Validation of the full-age spectrum equation in the approximation of glomerular filtration rate in Chinese patients with chronic kidney disease.

Introduction: To investigate the validity of the full age spectrum (FAS) equation in determining the glomerular filtration rate (GFR) in Chinese patients with chronic kidney disease (CKD) and to compare the performance of FAS equation and the technetium-99m-diethylene triamine pentaacetic acid (Tc-99m-DTPA) renal dynamic imaging method. Methods: The GFR was determined by three methods in the same day: (a) Tc-99m-DTPA dual plasma sample clearance method (mGFR); (b) FAS equation (eGFR1); (c) Tc-99m-DTPA renal dynamic imaging method (eGFR2). The mGFR was used as the reference standard. The Bland-Altman method, concordance correlation coefficient and regression equation were applied to evaluate the validity of the estimated glomerular filtration rate (eGFR). The bias, precision and accuracy were analyzed to compare the performances of eGFR1 and eGFR2. Results: A total of 162 subjects were enrolled in this study. The eGFR1 was correlated well with mGFR (concordance correlation coefficient was 0.896, p < 0.0001) and the regression equation was mGFR = -0.374 + 1.029eGFR1 (p < 0001). The Bland-Altman analysis proved good agreement between the eGFR1 and mGFR. In comparison with eGFR2, the eGFR1 showed better performance on bias (-1.22 vs. 8.92, p < 0001), precision (15.69 vs. 18.36, p = 0.047) and 30% accuracy (75.31% vs. 59.26%, p = 0.0009) in all participants. Conclusions: The FAS equation is valid in determining the glomerular filtration rate in Chinese patients with chronic kidney disease. The Tc-99m-DTPA renal dynamic imaging method is less accurate than the FAS equation and cannot be employed as the reference method in assessing the performance of FAS equation.

Silicon improves salt tolerance by increasing root water uptake in Cucumis sativus L.

KEY MESSAGE: Silicon enhances root water uptake in salt-stressed cucumber plants through up-regulating aquaporin gene expression. Osmotic adjustment is a genotype-dependent mechanism for silicon-enhanced water uptake in plants. Silicon can alleviate salt stress in plants. However, the mechanism is still not fully understood, and the possible role of silicon in alleviating salt-induced osmotic stress and the underlying mechanism still remain to be investigated. In this study, the effects of silicon (0.3 mM) on Na accumulation, water uptake, and transport were investigated in two cucumber (Cucumis sativus L.) cultivars ('JinYou 1' and 'JinChun 5') under salt stress (75 mM NaCl). Salt stress inhibited the plant growth and photosynthesis and decreased leaf transpiration and water content, while added silicon ameliorated these negative effects. Silicon addition only slightly decreased the shoot Na levels per dry weight in 'JinYou 1' but not in 'JinChun 5' after 10 days of stress. Silicon addition reduced stress-induced decreases in root hydraulic conductivity and/or leaf-specific conductivity. Expressions of main plasma membrane aquaporin genes in roots were increased by added silicon, and the involvement of aquaporins in water uptake was supported by application of aquaporin inhibitor and restorative. Besides, silicon application decreased the root xylem osmotic potential and increased root soluble sugar levels in 'JinYou 1.' Our results suggest that silicon can improve salt tolerance of cucumber plants through enhancing root water uptake, and silicon-mediated up-regulation of aquaporin gene expression may in part contribute to the increase in water uptake. In addition, osmotic adjustment may be a genotype-dependent mechanism for silicon-enhanced water uptake in plants.

[Pollution Characteristics, Source Apportionment, and Meteorological Response of Water-soluble Ions in PM2.5 in Xinxiang, North China].

Pollution variation, source characteristics, and meteorological effects of water-soluble inorganic ions (WSIIs) in PM2.5 were analyzed in Xinxiang city, Henan Province. PM2.5 samples and their chemical components were monitored online by using URG-9000 in four seasons:winter (January, 2022), spring (April, 2022), summer (July, 2022), and fall (October, 2022). The results showed that the TWSIIs had the same seasonal fluctuations as PM2.5. The average seasonal concentrations of WSIIs ranged from 19.62-72.15 µg·m-3, accounting for more than 60% of PM2.5, demonstrating that WSIIs were the major components of PM2.5. The annual concentration value of NO3-/SO42- was 2.11, which showed an increasing trend, suggesting predominantly mobile sources for secondary inorganic aerosols (SNA). Further, the molar concentration value [NH4+]/[NO3-] was 1.95, demonstrating that agriculture emissions were the dominant contributors to atmospheric nitrogen. Furthermore, the backward trajectory analysis showed that the concentrations of Ca2+ and Mg2+ were higher when the northeasterly wind prevailed and the wind speed was high. High values of SOR and NOR were correlated with low temperatures and high relative humidity (T < 8℃, RH > 60%), demonstrating that more gaseous precursors were converted into sulfate and nitrate. At high temperatures (T > 24℃), there was no apparent high NOR value like that for SOR, mainly due to the decomposition of NH4NO3 at high temperatures. Finally, backward trajectories associated with the PMF-resolved results were used to explore the regional transport characteristics. The results illustrated that dust sources in the study areas were mainly influenced by air trajectories originating from the northwest regions, whereas secondary sulfate, secondary nitrate, and biomass sources contributed more to WSIIs when wind speed and altitude air masses were low in the area surrounding the observation site.

Incidental bone metastases identified by renal dynamic scintigraphy: A case report.

INTRODUCTION: The Technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA) renal dynamic scintigraphy is widely used to evaluate the split renal function and continuously demonstrate the whole urinary collecting system. Furthermore, the extrarenal uptake of technetium-99m DTPA can provide useful information for the patients. CASE PRESENTATION: We described a 72-year-old male with a history of flank pain for 8 months and gross hematuria for 3 days. The technetium-99m diethylenetriaminepenta-acetic acid (DTPA) renal dynamic scintigraphy was performed to evaluate the split renal function. Unexpectedly, there were 2 foci of abnormal increased tracer uptake in the midline of the abdomen. The diagnosis of renal cancer was made on the basis of the imaging characteristics on the ultrasonography. The 2 foci with elevated DTPA activity were consistent with bone metastases on the images of computed tomography and magnetic resonance. CONCLUSION: The bone metastasis is one of the etiologies of the extrarenal uptake of technetium-99m DTPA, especially for the patients with several foci.

Camurati-Engelmann disease-a rare cause of tetany identified on bone scintigraphy: A case report.

RATIONALE: Camurati-Engelmann disease (i.e., progressive diaphyseal dysplasia) is an extremely rare autosomal dominant bone disorder. The most common clinical manifestations were chronic skeletal pain, waddling gait, muscular weakness. PATIENT CONCERNS: We described that a 27-year-old male with a 1-year history of intermittent tetany was referred for bone scintigraphy. The whole body bone scan images showed abnormal increased uptake of the tracer in the long bones of the upper and lower extremities as well as in the skull. DIAGNOSES: Combined the family history, the findings of the images and the genetic study, the diagnosis of Camurati-Engelmann disease was confirmed. INTERVENTIONS AND OUTCOMES: The patient responded well to the treatment of calcium gluconate. LESSONS: Bone scintigraphy would be helpful in the diagnosis and assessing the severity of Camurati-Engelmann disease.