Arterial Hypertension Is Associated with Increased Serum Lipoprotein(a) Levels in End‐Stage Renal Disease Patients

In addition to disorders in lipoprotein metabolism, several other factors are involved in the development of atherosclerotic changes in end‐stage renal disease (ESRD) patients. One of these is arterial hypertension. We evaluated serum lipids—total cholesterol (TC), triglycerides (TG), apolipoproteins (A_I , A _II , B, E), lipoprotein(a) [Lp(a)]—in 109 ESRD patients on dialysis [46 on hemodialysis (HD); 63 on continuous ambulatory peritoneal dialysis (CAPD)] and in 45 hyperlipidemic patients without renal failure (HL group). Dialysis patients were divided in two groups. Group A included 42 hypertensive patients (mean age: 62.3 ± 15.5 years) whose blood pressure (BP) was satisfactorily controlled with anti‐hypertensive medications. Group B included 67 non hypertensive patients (mean age: 66.6 ± 11.9 years). Levels of Lp(a) were significantly higher in both the HD (p = 0.001) and the CAPD (p < 0.05) patients as compared with the HL group. When the HD and CAPD groups were divided into hypertensive and non hypertensive patients, Lp(a) levels were significantly higher in the hypertensive patients; this difference was not observed among non renal failure patients. These results indicate that arterial hypertension is associated with elevated Lp(a) serum levels in ESRD patients undergoing either HD or CAPD.     

Exceedingly Small Gadolinium Oxide Nanoparticles with Remarkable Relaxivities for Magnetic Resonance Imaging of Tumors

Gd chelates have occupied most of the market of magnetic resonance imaging (MRI) contrast agents for decades. However, there have been some problems (nephrotoxicity, non‐specificity, and low r₁) that limit their applications. Herein, a wet‐chemical method is proposed for facile synthesis of poly(acrylic acid) (PAA) stabilized exceedingly small gadolinium oxide nanoparticles (ES‐GON‐PAA) with an excellent water dispersibility and a size smaller than 2.0 nm, which is a powerful T₁‐weighted MRI contrast agent for diagnosis of diseases due to its remarkable relaxivities (r₁ = 70.2 ± 1.8 mM^?1 s^?1, and r₂/r₁ = 1.02 ± 0.03, at 1.5 T). The r₁ is much higher and the r₂/r₁ is lower than that of the commercial Gd chelates and reported gadolinium oxide nanoparticles (GONs). Further ES‐GON‐PAA is developed with conjugation of RGD2 (RGD dimer) (i.e., ES‐GON‐PAA@RGD2) for T₁‐weighted MRI of tumors that overexpress RGD receptors (i.e., integrin α_vβ₃). The maximum signal enhancement (ΔSNR) for T₁‐weighted MRI of tumors reaches up to 372 ± 56% at 2 h post‐injection of ES‐GON‐PAA@RGD2, which is much higher than commercial Gd‐chelates (<80%). Due to the high biocompatibility and high tumor accumulation, ES‐GON‐PAA@RGD2 with remarkable relaxivities is a promising and powerful T₁‐weighted MRI contrast agent.     

Serum coenzyme Q10 levels are associated with coronary flow reserve in hemodialysis patients

Accelerated atherosclerosis is the major cause of mortality in patients on chronic hemodialysis (HD). The aim of this study was to evaluate the relation between coenzyme Q10 (CoQ10) levels and coronary flow reserve (CFR) in HD patients as an indicator of atherosclerosis. Seventy‐one chronic HD patients and 65 age‐ and sex‐matched healthy individuals were included in the study. Plasma CoQ10 levels were performed by high‐performance liquid chromatography measurements. CFR was assessed by transthoracic Doppler echocardiography. Serum CoQ10 levels (1.36 ± 0.43 vs. 2.53 ± 0.55, P < 0.001) and CFR values (1.73 ± 0.11 vs. 2.32 ± 0.28, P < 0.001) were significantly lower in HD patients compared with controls. There was a significant positive correlation between CFR and serum levels of CoQ10 (r = 0.669, P < 0.001). A linear regression analysis showed that serum levels of CoQ10 were still significantly and positively correlated with CFR (regression coefficient = 0.235, P < 0.001). Our data have demonstrated that HD patients exhibit decreased plasma CoQ10 levels and CFR values. The study also showed for the first time that serum CoQ10 levels independently predict CFR in HD patients.     

Effect of Valsalva Maneuver on QT Dispersion in Hemodialysis Patients

Increased QT dispersion seems to be related to an increased risk of arrhythmia and sudden death, a common cause of mortality in hemodialysis (HD) patients. Increase in sympathetic tone has been documented in HD patients. In this study, we aimed to investigate the effect of changes in the autonomic tone on QT dispersion (QTd) in HD patients. Twenty HD patients (M/F 13/7; age, mean ±SD, 28 ± 10 years) and 22 age‐ and sex‐matched healthy controls (M/F 12/10; age, 30 ± 10 years) were included. The patients were dialyzed three‐times weekly; time on dialysis was 17 ± 8 months. The QT durations were measured from 12 lead surface EKGs and were corrected for RR intervals. Corrected maximum (QT_c max) and minimum (QT_cmin) QT intervals and their difference (QT _c d) were recorded. The effect of the Valsalva maneuver in the release phase on QT _c intervals and dispersion was assessed. The HD patients had prolonged values compared to controls: QT _c d, 59 ± 17 ms versus 35 ± 7 ms, p < 0.001; QT _c max, 458 ± 41 ms versus 397 ± 21 ms, p < 0.001; and QT _c min, 398 ± 36 ms versus 362 ± 25 ms, p < 0.001. After the Valsalva maneuver no changes were observed in controls: QT _c max, 397 ± 21 ms versus 396 ± 22 ms, p = 0.9; QT _c min, 362 ± 24 ms versus 358 ± 19 ms, p = 0.5; and QT _c d, 35 ± 7 ms versus 38 ± 10 ms, p = 0.15. Whereas, in HD patients all values were significantly shortened: QT_cmax, 458 ± 41 ms versus 427 ± 35 ms, p = 0.003; QT_c min, 398 ± 36 ms versus 379 ± 34 ms, p = 0.04; and QT_c d, 59 ± 17 ms versus 48 ± 15 ms, p = 0.01. The decrease in QTmax was more prominent than the decrease in QTmin, hence QT dispersion was significantly decreased after the Valsalva maneuver, but differences from controls were still significant. In conclusion, increased sympathetic activity may have a role in the prolonged QT duration and increased QT dispersion in HD patients.     

The effect of zinc deficiency on salt taste acuity,preference, and dietary sodium intake in hemodialysis patients

Introduction High sodium intake is the main cause of fluid overload in hemodialysis (HD) patients, leading to increased cardiovascular mortality. High sodium intake is known to be associated with low salt taste acuity and/or high preference. As the zinc status could influence taste acuity, we analyzed the effect of zinc deficiency on salt taste acuity, preference, and dietary sodium intake in HD patients. Methods A total of 77 HD patients was enrolled in this cross‐sectional study. Zinc deficiency was defined as serum zinc level with below 70 µg/mL. The patients were divided into two groups based on serum zinc level. Salt taste acuity and preference were determined by a sensory test using varying concentrations of NaCl solution, and dietary sodium intake was estimated using 3‐day dietary recall surveys. Findings The mean salt recognition threshold and salt taste preference were significantly higher in the zinc deficient group than in the non‐zinc deficient group. And there was significant positive correlation between salt taste preference and dietary sodium intake in zinc deficient group (r = 0.43, P = 0.002). Although, the dietary sodium intake showed a high tendency with no significance (P = 0.052), interdialytic weight gain was significantly higher in the zinc deficient group than in the non‐zinc deficient group (2.68 ± 1.02 kg vs. 3.18 ± 1.02 kg; P = 0.047). Discussion Zinc deficiency may be related to low salt taste acuity and high salt preference, leading to high dietary sodium intake in HD patients.     

The Clinical Impact of Increasing the Hemodialysis Dose

Good evidence suggests that improvements in dialysis efficiency reduce morbidity and mortality of hemodialysis (HD) patients. Dialysis efficiency has also been related to better control of arterial blood pressure (BP), anemia, and serum phosphorus levels, and to improvement in patients' nutritional status. Over a 2‐year period, the present self‐controlled study of 34 HD patients (23 men, 11 women; age, 52.6 ± 14.5 years; HD duration, 55.9 ± 61.2 months) looked at the effect on clinical and laboratory parameters of increasing the delivered dialysis dose under a strict dry‐weight policy. Dialysis dose was increased without increasing dialysis time and frequency. A statistically significant increase was seen in delivered HD dose: the urea reduction ratio (URR) increased to 60% ± 10% from 52% ± 8%, and then to 71% ± 7% (p < 0.001); Kt/V_urea increased to 1.22 ± 0.28 from 0.93 ± 0.19, and then to 1.55 ± 0.29 (p < 0.001). A statistically significant increase in hemoglobin concentration also occurred—to 10.8 ± 1.9 g/dL from 10.4 ± 1.7 g/dL, and then to 11.0 ± 1.3 g/dL (p < 0.05 as compared to baseline)—with no significant difference in weekly erythropoietin dose. Statistically significant decreases occurred in the systolic and diastolic blood pressures during the first year; they then remained unchanged. Systolic blood pressure decreased to 131 ± 23 mmHg from 147 ± 24 mmHg (p < 0.001); diastolic blood pressure decreased to 65 ± 11 mmHg from 73 ± 12 mmHg (p < 0.001). Serum albumin increased insignificantly to 4.4 ± 0.4 g/dL from 4.3 ± 0.4 g/dL, and then significantly to 4.6 ± 0.3 g/dL (p = 0.002 as compared to both previous values). Normalized protein catabolic rate increased significantly to 1.16 ± 0.15 g/kg/day from 0.93 ± 0.16 g/kg/ day (p < 0.001), and then to 1.20 ± 0.17 g/kg/day (p < 0.001 as compared to baseline). We conclude that the increases achieved in average Kt/V_urea per hemodialysis session by increasing dialyzer membrane area, and blood and dialysate flows, without increasing dialysis time above 4 hours, in patients hemodialyzed thrice weekly, coupled with strict dry‐weight policy, resulted in improvements in hypertension, nutritional status, and anemia.     

A Comparative Study of C‐Reactive Protein Plasma Levels in Patients on Hemodialysis and Peritoneal Dialysis

In dialysis patients, C‐reactive protein (CRP), a well‐recognized marker of inflammation, predicts mortality. Higher levels have been described in hemodialysis (HD) patients as compared with peritoneal dialysis (PD) patients. Our aim was to determine, based on CRP plasma levels, the degree of inflammation in HD patients using low‐permeability polysulfone membranes and relatively pure dialysate, and that in PD patients. A secondary objective was to study factors associated with hypoalbuminemia and inflammation in both populations. We studied 69 stable patients on dialysis (32 on HD and 37 on PD). The mean age was 69.9 ± 8.2 years, and the mean time on dialysis was 27 months. The two populations were comparable for overall and cardiovascular comorbidities. Nephelometry was used to measure CRP plasma levels (normal levels < 0.6 mg/dL). The Kt/V_urea, corrected for residual renal clearance, and the equivalent of protein nitrogen appearance (PNA) were also calculated. Of the patients studied, 53% showed CRP plasma levels higher than 0.6 mg/dL; in 36%, the levels were higher than 1 mg/dL. No significant differences in these percentages were noted between the two dialysis groups. Patients with CRP levels higher than 1 mg/dL showed lower serum albumin, iron, hemoglobin, and transferrin levels, and higher ferritin values and leukocyte counts. Under logistic regression analysis, CRP levels higher and lower than 1 mg/dL were significantly associated with serum albumin [p = 0.01; odds ratio (OR): 0.15], iron (p = 0.006; OR: 0.96), transferrin (p = 0.004; OR: 0.97), and hemoglobin (p = 0.02; OR: 0.67). Serum albumin levels were significantly lower in PD patients. Under regression analysis, serum albumin levels correlated with cholesterol (r: 0.25; p = 0.04), serum iron (r: 0.5; p = 0.0001), transferrin (r: 0.3; p = 0.015), ultrafiltration capacity (r: 0.42; p = 0.008), and CRP values above 0.6 mg/dL (r: –0.65; p = 0.001). In conclusion, the frequent elevation of CRP plasma levels observed in both HD and PD patients suggests the presence of a silent inflammatory state. Hemodialysis performed with biocompatible, low‐permeability membranes is not associated with higher CRP plasma levels than those seen in PD. In both groups, hypoalbuminemia is related to CRP level. Levels of serum albumin, slightly lower in PD patients, are also related to peritoneal ultrafiltration capacity.     

Effect of Vitamin E Dialyzer Membrane on Anemia in Hemodialysis Patients

Red blood cell (RBC) survival in patients on chronic maintenance hemodialysis (HD) has been reported to be shortened due to the oxidative damage of RBC membrane. The use of antioxidants might help in the control of anemia and reduce the erythropoietin (EPO) dose needed. Objective: The objective was to determine the effects of vitamin E‐bonded dialyzer membrane (VEM) on anemia and EPO requirements in chronic HD patients. Patients and methods: We prospectively studied 19 stable patients on HD (8 males, age 58.47, range 31–76 years) who were shifted from other dialyzer membranes to VEM for 6 months. At baseline they were given a mean dose of EPO of 90.6 ± 51 U kg^–1 BW^–1 week^–1. Clinical data, dry body weight corrected pre‐dialysis RBC, hemoglobin, reticulocytes, serum iron and ferritin, complete biochemistry, iPTH, and CRP were studied at 3 and 6 months, while therapy scheme was reevaluated monthly. Results: A significant rise, compared to the baseline, was found in hemoglobin and in RBC at 3 months of treatment (12.44 ± 1.16 g/dL vs. 11.2 ± 1.2 g/dL, p = 0.002; and 4.01 ± 0.53 × 10⁶/μL vs. 3.64 ± 0.5 × 10⁶/μL, p < 0.05) and at the end of follow‐up (12.17 ± 1.33 g/dL vs. 11.2 ± 1.2 g/dL, p < 0.05; and 4.03 ± 0.53 × 10⁶/μL vs. 3.64 ± 0.5 × 106/μL, p < 0.05). No significant change in serum iron and ferritin, reticulocytes, EPO dose used, iPTH, Kt/V, or CRP was found at the end of follow‐up compared to the baseline (68.8 ± 17 mg/dL vs. 67.9 ± 18 mg/dL, p = NS; 421 ± 296 mg/dL vs. 478 ± 359 mg/dL, p = NS; 3.76 ± 0.89 × 10⁴/μL vs. 3.82 ± 0.78 × 10⁴/μL, p = NS; 90.2 ± 53 U kg^–1 BW^–1 week^–1 vs. 90.6 ± 51 U kg^–1 BW^–1 week^–1, p = NS; 157 ± 43 pg/dL vs. 148 ± 56 pg/dL, p = NS; 1.21 ± 0.22 vs. 1.2 ± 0.17, p = NS; 7.15 ± 5.42 mg/L vs. 15.38 ± 29.8 mg/L, p = NS, respectively). Conclusions: Despite the small number of patients and the short time interval of treatment, an antioxidant effect of VEM apparently achieved early a better control of anemia in HD patients.     

Patient‐specific phosphorus mobilization clearance during nocturnal and short daily hemodialysis

The kinetics of plasma phosphorus during different hemodialysis (HD) modalities are incompletely understood. We recently demonstrated that a pseudo one‐compartment kinetic model including phosphorus mobilization from various body compartments into extracellular fluids can describe intradialytic and postdialytic rebound kinetics of plasma phosphorus during conventional and short 2‐hour HD treatments. In this model, individual patient differences in phosphorus kinetics were characterized by a single parameter, the phosphorus mobilization clearance (K_M). In this report we determined K_M in patients treated by in‐center nocturnal HD (ICNHD) and short daily HD (SDHD) with low dialyzer phosphate clearance. In the ICNHD study, eight patients underwent 8‐hour HD treatments where intradialytic and postdialytic plasma samples were collected; K_M values were determined by nonlinear regression of plasma concentration as a function of time. In the SDHD study, five patients were studied during 28 treatments for approximately 3 hours. Here, K_M was calculated using only predialytic and postdialytic plasma phosphorus concentrations. Dialyzer phosphate clearances were 134 ± 20 (mean ± SD) and 95 ± 16 mL/min during ICNHD and SDHD, respectively. K_M values for the respective therapies were 124 ± 83 and 103 ± 33 mL/min, comparable to those determined previously during conventional and short HD treatments of 98 ± 44 mL/min. When results from ICNHD, SDHD, and previous HD modalities were combined, K_M was directly correlated with postdialytic body weight (r = 0.38, P = 0.025) and inversely correlated with predialytic phosphorus concentration (r = ?0.47, P = 0.005). These findings suggest that phosphorus kinetics during various HD modalities can be described by a pseudo one‐compartment model.     

Concordance of absolute and relative plasma volume changes and stability of Fcells in routine hemodialysis

Central hematocrit (H) measurements are currently used to track the degree of ultrafiltration‐induced hemoconcentration with the aim to detect and prevent excessive intravascular fluid depletion during hemodialysis (HD). Failure to maintain hemodynamic stability is commonly attributed to the misinterpretation of H caused by an unaccountable increase in F_cells, the ratio of whole‐body hematocrit to H. It was the aim to examine F_cells under everyday conditions in a group of stable HD patients. Absolute plasma volume (V_p) and H were concomitantly measured during routine HD in the extracorporeal system in hourly intervals by noninvasive and continuous technology (CritLine‐Instrument‐III) and indocyanine green dye dilution to derive relative plasma volumes from V_p and H (RPV_p, RPV_H), respectively, and to calculate F_cells. Thirteen patients were studied during two midweek treatments (n = 26). Both absolute V_p (P < 0.05) and relative plasma volumes RPV_H (P < 0.001) decreased during HD. V_p at any time point was positively correlated to RPV_H (r = 0.52). Moreover, relative plasma volumes RPV_H and RPV_p determined by independent techniques were identical and showed negligible bias (?0.2%) but considerable limits of agreement (?15.6% to +15.3%). F_cells was stable and in the range of 0.9 ± 0.05 throughout HD and not different from the value assumed at the beginning of HD. Although F_cells remains constant in patients on routine dialysis and relative plasma volumes (RPV_H and RPV_p) determined by independent techniques are therefore comparable, the variability of experimental conditions during dialysis and the limited accuracy of absolute volume measurements using available technology continues to complicate the ultrafiltration control problem.     

Phosphate binders and metabolic acidosis in patients undergoing maintenance hemodialysis—sevelamer hydrochloride,calcium carbonate,and bixalomer

The serum bicarbonate (HCO₃^–) levels are decreased in chronic hemodialysis (HD) patients treated with sevelamer hydrochloride (SH). We assessed the effects of bixalomer on the chronic metabolic acidosis in these patients. We examined 12 of the 122 consecutive Japanese patients with end‐stage renal disease on HD, who orally ingested a dose of SH (≥2250 mg), and an arterial blood gas analysis and biochemical analysis were performed before HD. Patients whose serum HCO₃^– levels were under 18 mmol/L were changed from SH to the same dose of bixalomer. A total of 12 patients were treated with a large amount of SH. Metabolic acidosis (a serum HCO₃^– level under 18 mmol/L) was found in eight patients. These patients were also treated with or without small dose of calcium carbonate (1.2 ± 1.1 g). The dose of SH was changed to that of bixalomer. After 1 month, the serum HCO₃^– levels increased from 16.3 ± 1.4 to 19.6 ± 1.7 mmol/L (P < 0.05). Metabolic acidosis was not observed in four patients (serum HCO₃^– level: 20.3 ± 0.7 mmol/L) likely because they were taking 3 g of calcium carbonate with SH. In the present study, the development of chronic metabolic acidosis was induced by HCl containing phosphate binders, such as SH, and partially ameliorated by calcium carbonate, then subsequently improved after changing the treatment to bixalomer.     

Regional Anticoagulation with Sodium Citrate in Pediatric Patients on Intermittent Hemodialysis Therapy with Bleeding Risks

Heparin‐free anticoagulation in hemodialysis (HD) is advocated for patients with clotting abnormalities and risk of bleeding. Objective: First publication on regional citrate anticoagulation (RCA) in children. RCA is free from systemic effects, guarantees excellent dialyzer life, but requires careful monitoring. Methods: We report on 3 patients treated by intermittent RCA HD (4 h each, high‐flux dialyzer F40, Fresenius): (1) 17‐year‐old boy (renal transplant failure, access via cubital Cimino fistula) after hypertensive intra‐cerebral hemorrhage (2 sessions); (2) 13‐year‐old girl (hemolytic uremic syndrome, access via jugular vein Shaldon catheter) after abdominal surgery and bleeding (8 sessions); and (3) 7‐year‐old boy (hyperoxaluria, access via PermCath^® jugular vein catheter) after renal transplant biopsy (3 sessions). Sodium citrate 30% was infused into the extra corporeal circuit (blood flow 150 mL/min) before dialyzer (initial flow 30 mL/min) and calcium gluconate 10% for antidote into venous line near of catheter or fistula (initial flow 40 mL/min). Post‐dialyzer extracorporeal serum Ca⁺⁺ (aim < 0.3 mmol/L) and pre‐dialyzer intra‐corporeal Ca⁺⁺ (aim > 0.9) were measured for every 30 min. Serum Na⁺, K⁺, base excess (BE), blood flow, blood pressure, heart rate, and blood out‐flow and in‐flow pressure were also monitored. Results: For adequate RCA (mean extracorporeal serum Ca⁺⁺ 0.24 ± 0.04 mmol/L), a mean citrate flow of 36.1 ± 5.9 mL/h and a mean calcium substitution rate of 40.8 ± 3.4 mL/h were needed. Intra‐corporeal Ca⁺⁺ was kept at 1.10 ± 0.07 mmol/L. Extracorporeal activated clotting time (ACT) was 194 ± 41 and intra‐corporeal ACT 90 ± 12 sec. Serum Na⁺, K⁺, and BE during HD were 138 ± 2, 3.5 ± 0.3, and ?0.6 ± 1.1 mmol/L, respectively. Mean arterial blood pressures of patients 1–3 were 117 ± 5, 103 ± 5, and 102 ± 6 mmHg. All patients were stable and without any bleeding during HD. The only adverse event was 1 episode of hypocalcemia (Ca⁺⁺ < 0.6 mmol/L) cured by stopping dialysis. Conclusions: Local anticoagulation with sodium citrate during intermittent HD can be applied safely in children and adolescents.     

Phosphate removal model: an observational study of low-flux dialyzers in conventional hemodialysis therapy

Precise assessing phosphate removal by hemodialysis (HD) is important to improve phosphate control in patients on maintenance HD. We reported a simple noninvasive model to estimate phosphate removal within a 4‐hour HD. One hundred sixty‐five patients who underwent HD 4 hours per session using low‐flux dialyzers made of polysulfone (1.2 m²) or triacetate (1.3 m²) were enrolled. Blood flows varied from 180 to 300 mL/min. Effluent dialysate samples were collected during the 4‐hour HD treatment to measure the total phosphate removal. Predialysis levels of serum phosphate, potassium, hematocrit, intact parathyroid hormone, total carbon dioxide (TCO₂), alkaline phosphatase, clinical and dialysis characteristics were obtained. One hundred thirty‐five observations were randomly selected for model building and the remaining 30 for model validation. Total amount of phosphate removal within the 4‐hour HD was mostly 15–30 mmol. A primary model (model 1) predicting total phosphate removal was Tpo₄ = 79.6 × C₄₅ (mmol/L) ? 0.023 × age (years) + 0.065 × weight (kg) ? 0.12 × TCO₂ (mmol/L) + 0.05 × clearance (mL/min) ? 3.44, where C₄₅ was phosphate concentration in spent dialysate measured at the 45 minute of HD and clearance was phosphate clearance of dialyzer in vitro conditions offered by manufacturer's data sheet. Since the parameter TCO₂ needed serum sample for measurement, we further derived a noninvasive model (model 2):Tpo₄ = 80.3 × C₄₅ ? 0.024 × age + 0.07 × weight + 0.06 × clearance ? 8.14. Coefficient of determination, root mean square error, and residual plots showed the appropriateness of two models. Model validation further suggested good and similar predictive ability of them. This study derived a noninvasive model to predict phosphate removal. It applies to patients treated by 4‐hour HD under similar conditions.     

Dotted Core–Shell Nanoparticles for T1‐Weighted MRI of Tumors

Gd‐based T ₁‐weighted contrast agents have dominated the magnetic resonance imaging (MRI) contrast agent market for decades. Nevertheless, they are reported to be nephrotoxic and the U.S. Food and Drug Administration has issued a general warning concerning their use. In order to reduce the risk of nephrotoxicity, the MRI performance of the Gd‐based T ₁‐weighted contrast agents needs to be improved to allow a much lower dosage. In this study, novel dotted core–shell nanoparticles (FeGd‐HN3‐RGD2) with superhigh r ₁ value (70.0 mM^?1 s^?1) and very low r ₂/r ₁ ratio (1.98) are developed for high‐contrast T ₁‐weighted MRI of tumors. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay and histological analyses show good biocompatibility of FeGd‐HN3‐RGD2. Laser scanning confocal microscopy images and flow cytometry demonstrate active targeting to integrin α_vβ₃ positive tumors. MRI of tumors shows high tumor ΔSNR for FeGd‐HN3‐RGD2 (477 ± 44%), which is about 6‐7‐fold higher than that of Magnevist (75 ± 11%). MRI and inductively coupled plasma results further confirm that the accumulation of FeGd‐HN3‐RGD2 in tumors is higher than liver and spleen due to the RGD2 targeting and small hydrodynamic particle size (8.5 nm), and FeGd‐HN3‐RGD2 is readily cleared from the body by renal excretion.     

Enhanced solute removal with intermittent, in-center, 8-hour nocturnal hemodialysis

Advances in the dialysis technique and increasing urea Kt/V have not improved outcomes for end‐stage renal disease patients maintained on hemodialysis (HD) therapy. Attention has, thus, focused on enhancing solute removal via prolonged HD sessions. A reduction in the serum levels of phosphorus and β‐2‐microglobulin (B2M) with longer HD treatments has been linked to improved patient outcomes. We have shown that serum phosphorus levels are significantly lowered in patients maintained on thrice‐weekly, in‐center, 8‐hour nocturnal HD performed at a blood flow rate of 400 mL/min. The kinetics of this modality were examined. A total of 8 patients participated in the study (age 45±7 years). Serum creatinine levels decreased from 9.2±1.9 to 3.0±1.0 mg/dL at 8 hours while serum phosphorus decreased from 5.7±1.9 to 2.5±0.7 mg/dL at 8 hours. The initial decrease from predialysis values to 1 hour after the start of HD was significant for both creatinine (P<0.0001) and phosphorus (P<0.001). Serum B2M decreased from 26.8±5.5 mg/L predialysis to 14.9±7.0 mg/L at 8 hours (P<0.01). Dialysate‐side clearances of phosphorus and creatinine were 136±13 and 143±27 cm³/min, respectively. Phosphorus clearances were steadily maintained during the 8‐hour session. A total of 904±292 mg of phosphorus was removed during the 8‐hour treatment, with 501±174 mg (55%) removed during the first 4 hours and the remaining 45% continuously removed during the latter one‐half of the session. The overall calculated B2M clearance was 55.1±40.3 cm³/min using the immediate post‐B2M value and 28.4±34.2 mg/L using the 30‐minute postdialysis value for the calculation. Serum levels of phosphorus and B2M decrease dramatically during an 8‐hour session. Future studies are necessary to determine whether the enhanced solute removal with longer HD sessions translates into an improved outcome for HD patients.     

Prevalence of hypothyroidism and thyroid nodule in chronic hemodialysis Iranian patients

Introduction: End stage renal disease (ESRD) reasons several changes in the function of thyroid gland as; lower levels of thyroid hormones, altered hormone metabolism, and increased iodine storage. The aim of this study was to evaluate the prevalence of nodular goiter and hypothyroidism in hemodialysis (HD) patients compared with normal population. Methods: This cross‐sectional study was conducted among HD patients and healthy people as the control group for thyroid function evaluation. Thyroid gland was evaluated by physical examination and ultrasonography. Blood level of FT3, FT4, TSH, TPO Ab, and urinary iodine excretion were checked in both groups. Data were analyzed using SPSS‐17 and P‐value less than 0.05 was considered as the significance level. Findings: Eighty six HD patients (57.2 ± 17.2 mean age, 48 men) and 86 healthy people (56.6 ± 16.8 mean age, 48 men) were enrolled in this study. Goiter was confirmed by physical examination in 29.0% of the HD patients and 12.8% of the control group (P = 0.04). Nodular goiter that was shown by ultrasonography was found in 27.9% and 3.5% of the HD and control groups, respectively (P = 0.01). HD patients had a higher frequency of reduced FT3 (40.9% vs. 4.6%, P < 0.01) and increased TSH (18.6% vs. 8.1%, P < 0.03(. TPO Ab was positive in 15.1% of the HD and 11.6% of the control groups (P = 0.14). Discussion: The high incidence of nodular goiter and hypothyroidism in ESRD patients shows that screening for thyroid dysfunction and goiter, using appropriate laboratory tests, should be considered in evaluations of ESRD patients.     

3D Anisotropic Thermal Conductivity of Exfoliated Rhenium Disulfide

ReS₂ represents a different class of 2D materials, which is characterized by low symmetry having 1D metallic chains within the planes and extremely weak interlayer bonding. Here, the thermal conductivity of single‐crystalline ReS₂ in a distorted 1T phase is determined at room temperature for the in‐plane directions parallel and perpendicular to the Re‐chains, and the through‐plane direction using time‐domain thermoreflectance. ReS₂ is prepared in the form of flakes having thicknesses of 60–450 nm by micromechanical exfoliation, and their crystalline orientations are identified by polarized Raman spectroscopy. The in‐plane thermal conductivity is higher along the Re‐chains, (70 ± 18) W m^?1 K^?1, as compared to transverse to the chains, (50 ± 13) W m^?1 K^?1. As expected from the weak interlayer bonding, the through‐plane thermal conductivity is the lowest observed to date for 2D materials, (0.55 ± 0.07) W m^?1 K^?1, resulting in a remarkably high anisotropy of (130 ± 40) and (90 ± 30) for the two in‐plane directions. The thermal conductivity and interface thermal conductance of ReS₂ are discussed relative to the other 2D materials.     

Ten‐Gram‐Scale Facile Synthesis of Organogadolinium Complex Nanoparticles for Tumor Diagnosis

The market of available contrast agents for clinical magnetic resonance imaging (MRI) has been dominated by gadolinium (Gd) chelates based T₁ contrast agents for decades. However, there are growing concerns about their safety because they are retained in the body and are nephrotoxic, which necessitated a warning by the U.S. Food and Drug Administration against the use of such contrast agents. To ameliorate these problems, it is necessary to improve the MRI efficiency of such contrast agents to allow the administration of much reduced dosages. In this study, a ten‐gram‐scale facile method is developed to synthesize organogadolinium complex nanoparticles (i.e., reductive bovine serum albumin stabilized Gd‐salicylate nanoparticles, GdSalNPs‐rBSA) with high r₁ value of 19.51 mm ^?1 s^?1 and very low r₂/r₁ ratio of 1.21 (B₀ = 1.5 T) for high‐contrast T₁‐weighted MRI of tumors. The GdSalNPs‐rBSA nanoparticles possess more advantages including low synthesis cost (≈0.54 USD per g), long in vivo circulation time (t_1/2 = 6.13 h), almost no Gd³⁺ release, and excellent biosafety. Moreover, the GdSalNPs‐rBSA nanoparticles demonstrate excellent in vivo MRI contrast enhancement (signal‐to‐noise ratio (ΔSNR) ≈ 220%) for tumor diagnosis.     

Reduction in sintering temperature and tunable microwave dielectric properties in NaCa4V5O17 via compositional engineering

Some Li⁺-substituted NaCa₄V₅O₁₇ ceramics were designed and fabricated by the solid-state reaction method. Effects of cation doping on the sintering behavior, crystal structure, microstructure, and dielectric properties were systematically studied. As expected, Li⁺ substitution effectively reduced the densification temperature of NaCa₄V₅O₁₇ ceramics and lower the relative permittivity (ε_r), but surprisingly increased the quality factor (Q×f). A composition with 20?mol% Li⁺ dopants exhibits the highest Q×f?=?66,000?±?124?GHz coupled with an ε_r of 10.4?±?0.1 and a τ_f of ? 81.3?±?1.4?ppm/°C. Such compositional dependence in dielectric properties was analyzed in terms of ionic polarization and packing fraction.

     

One‐Step,Room‐Temperature Synthesis of Glutathione‐Capped Iron‐Oxide Nanoparticles and their Application in In Vivo T1‐Weighted Magnetic Resonance Imaging

The room‐temperature, aqueous‐phase synthesis of iron‐oxide nanoparticles (IO NPs) with glutathione (GSH) is reported. The simple, one‐step reduction involves GSH as a capping agent and tetrakis(hydroxymethyl)phosphonium chloride (THPC) as the reducing agent; GSH is an anti‐oxidant that is abundant in the human body while THPC is commonly used in the synthesis of noble‐metal clusters. Due to their low magnetization and good water‐dispersibility, the resulting GSH‐IO NPs, which are 3.72 ± 0.12 nm in diameter, exhibit a low r₂ relaxivity (8.28 mm ^?1s^?1) and r₂/r₁ ratio (2.28)—both of which are critical for T₁ contrast agents. This, together with the excellent biocompatibility, makes these NPs an ideal candidate to be a T₁ contrast agent. Its capability in cellular imaging is illustrated by the high signal intensity in the T₁‐weighted magnetic resonance imaging (MRI) of treated HeLa cells. Surprisingly, the GSH‐IO NPs escape ingestion by the hepatic reticuloendothelial system, enabling strong vascular enhancement at the internal carotid artery and superior sagittal sinus, where detection of the thrombus is critical for diagnosing a stroke. Moreover, serial T₁‐ and T₂‐weighted time‐dependent MR images are resolved for a rat's kidneys, unveiling detailed cortical‐medullary anatomy and renal physiological functions. The newly developed GSH‐IO NPs thus open a new dimension in efforts towards high‐performance, long‐circulating MRI contrast agents that have biotargeting potential.