Effect of iodixanol and ioxilan on QT interval and renal function in patients with systolic heart failure

Background

Contrast media (CM) exposure is associated with a substantial risk of arrhythmias and nephrotoxicity. These adverse effects may be exacerbated in high-risk conditions such as heart failure, although no studies have evaluated newer CM agents in this population. This study evaluated the electrophysiologic and renal effects of two newer CM agents, iodixanol and ioxilan, in heart failure patients undergoing angiography.

Methods

Eighty-seven consecutive systolic heart failure patients who received either iso-osmolar iodixanol (n = 44) or low-osmolar ioxilan (n = 43), stratified for concomitant amiodarone, were evaluated for QT interval and serum creatinine changes in comparison to baseline. QT values were corrected according to three formulae: Bazett's correction, Fridericia formula, and Framingham equation.

Results

Baseline patient characteristics were not significantly different in the iodixanol versus ioxilan groups, except for myocardial infarction and renal disease. No significant change in mean QTc was observed after exposure to either CM agent compared to baseline. These results were unaffected by amiodarone. A significant improvement in serum creatinine from baseline was observed in the iodixanol group compared to the ioxilan group (−0.121 ± 0.35 mg/dL vs. 0.033 ± 0.23 mg/dL, respectively; p = 0.045).

Conclusions

No significant change in QTc interval was observed in patients receiving either iodixanol or ioxilan during angiography. Iodixanol appeared to improve short-term renal function in patients with heart failure and should be further investigated.     

Retinal microvascular calibre and risk of incident diabetes: the multi-ethnic study of atherosclerosis

Aim

To prospectively examine the association of retinal microvascular signs with incident diabetes and impaired fasting glucose (IFG) in a multi-ethnic population-based cohort.

Methods

The multi-ethnic study of atherosclerosis comprised Caucasians, African-Americans, Hispanics and Chinese aged 45-84 years. Retinal vascular calibre and retinopathy were quantified from baseline retinal photographs. Incident diabetes and IFG were ascertained prospectively.

Results

After a median follow-up of 3 years, 243 (4.9%) people developed diabetes and 565 (15.0%) developed IFG. After adjusting for known risk factors, participants with wider retinal arteriolar calibre had a higher risk of developing diabetes [HR: 1.60; 95% CI: 1.12-2.29, p = 0.011 comparing highest with lowest arteriolar calibre tertile]. In ethnic subgroup analysis, the association between wider retinal arteriolar calibre and incident diabetes was stronger and statistically significant only in Caucasians [HR: 2.78; 95% CI: 1.37-5.62, p = 0.005]. Retinal venular calibre and retinopathy signs were not related to risk of diabetes or IFG.

Conclusion

Wider retinal arteriolar calibre is independently associated with an increased risk of diabetes, supporting a possible role for early arteriolar changes in diabetes development. This effect was largely seen in Caucasians, and not in other ethnic groups, and may reflect ethnic differences in susceptibility to diabetes from microvascular pathways.     

Effect of Mica Reinforcement on the Flexural Strength and Microhardness of Polymethyl Methacrylate Denture Resin

Purpose : Conventional denture base polymethyl methacrylate (PMMA) is low in strength, soft, and brittle on impact. Improvements in the mechanical properties of denture base materials have been sought by adding different reinforcing phases to the PMMA matrix. The purpose of this work was to study the effects of mica reinforcement on the mechanical properties, flexural strength, and microhardness of PMMA denture base resin. Materials and Methods : Wet ground muscovite mica and Lucitone 199 original shade denture base resin were used. Two micas were tested: W200 and P66 with average particle sizes (d50) of 131 μm and 30 μm, respectively. The mica was silane treated in a solution of 3‐methacryloxypropyl trimethoxysilane, ethanol, and water, and then dried. The specimens were fabricated using the denture base resin manufacturer's instructions with a powder : liquid ratio of 21 g/10 ml and a mixing time of 30 seconds. Five treatment groups were produced with differing amounts of mica added to the PMMA denture base resin: (A) control group with 0 vol% mica, (B) 10 vol% W200 mica, (C) 20 vol% W200 mica, (D) 10 vol% P66 mica, (E) 20 vol% P66 mica. The mica replaced equal volumes of the PMMA powder component to minimize changes in viscosity. The three‐point bending flexural strength specimens were 70 × 11 × 3 mm³. Seven specimens were prepared for each treatment group. The hardness specimens were prepared from the ends of the three‐point bend specimens after they were broken (N = 7). After deflasking, the specimens were polished with 600 grit silicon carbide paper to achieve smooth surfaces. A standard three‐point bending jig with a span length of 50 mm was attached to an Instron universal testing machine. The specimens were placed on the jig, and loading was carried out using a 1 mm/min crosshead speed until failure. Microhardness was measured using a Clark microhardness tester with a Knoop indenter. The load was set to 200 g and the dwell time to 15 seconds. ANOVA and Tukey tests were used for statistical analyses (Alpha = 0.05). Results : The flexural strength of the control group was between 77% and 94% higher than all the mica‐containing groups (p≤ 0.05). No significant differences were found within the four mica groups. Microhardnesses of the 20% mica groups (both fine and coarse) were 33% and 26% higher than the control (p≤ 0.05). The 10% mica groups had higher hardness than the control group, but the increase was not statistically significant (p > 0.05). Conclusion : Mica additions to denture PMMA reduced flexural strength; however, with the specimens containing highest mica concentrations (20%), microhardness significantly increased.     

Insulin resistance and cognition among HIV-infected and HIV-uninfected adult women: the Women's Interagency HIV Study

Cognitive impairment remains prevalent in the era of combination antiretroviral therapy (cART) and may be partially due to comorbidities. We postulated that insulin resistance (IR) is negatively associated with cognitive performance. We completed a cross-sectional analysis among 1547 (1201 HIV(+)) women enrolled in the Women's Interagency HIV Study (WIHS). We evaluated the association of IR with cognitive measures among all WIHS women with concurrent fasting bloods and cognitive testing [Trails A, Trails B, and Symbol Digit Modalities Test (SDMT)] using multiple linear regression models. A smaller subgroup also completed the Stroop test (n=1036). IR was estimated using the Homeostasis Model Assessment (HOMA). Higher HOMA was associated with poorer performance on the SDMT, Stroop Color-Naming (SCN) trial, and Stroop interference trial, but remained statistically significant only for the SCN in models adjusting for important factors [β=3.78?s (95% CI: 0.48-7.08), p=0.025, for highest vs. lowest quartile of HOMA]. HIV status did not appear to substantially impact the relationship of HOMA with SCN. There was a small but statistically significant association of HOMA and reduced neuropsychological performance on the SCN test in this cohort of women.     

Clinical and mutational characteristics of spinal muscular atrophy with respiratory distress type 1 in the Netherlands

Spinal muscular atrophy with respiratory distress type 1 is an autosomal recessive disorder with early respiratory difficulties, distal muscle weakness, and contractures leading to foot deformities as the most striking clinical symptoms. Mutations of the gene encoding the immunoglobulin heavy chain μ-binding protein 2, mapped on chromosome 11q13, are the cause of the disease. We present the clinical and mutational characteristics of ten patients in the Netherlands who showed considerable clinical variability; they carried six novel mutations, including a deletion of exon 2. However, there were no clear phenotype–genotype correlations.     

Parameter control and property analysis in the preparation of platinum iodide nanocolloids through the electrical spark discharge method

This study employed the electrical spark discharge method to prepare platinum iodide nanocolloids at normal temperature and pressure. Wires composed of 99.5% platinum were applied as the electrodes, and 250 ppm liquid iodine was employed as the dielectric fluid. An electric discharge machine was applied to generate cyclic direct current pulse power between the electrodes. Five sets of turn-on and turn-off time (T_on–T_off) parameters, namely 10–10, 30–30, 50–50, 70–70, and 90–90 μs, were implemented to identify the optimal nanocolloid preparation conditions. An ultraviolet-visible spectroscope, a Zetasizer, and a transmission electron microscope were used to examine the nanocolloids'' properties. The results revealed that the T_on–T_off parameter set of 10–10 μs was the most ideal setting for platinum iodide nanocolloid preparation. With this parameter set, the characteristic wavelengths of the nanocolloid were 285 and 350 nm, respectively; its absorbance values were 0.481 and 0.425, respectively; and its zeta potential and particle size were −30.3 mV and 61.88 nm, respectively. This parameter set yielded maximized absorbance, satisfactory suspension stability, and minimized nanoparticle sizes for the nanocolloid.

This study employed the electrical spark discharge method to prepare platinum iodide nanocolloids at normal temperature and pressure.