Long-term changes in serum silver concentrations after extremity reconstruction with silver-coated megaprostheses.

Silver-coated megaprostheses are considered to reduce infection rate following reconstruction of bone defects in tumour surgery or revision arthroplasty. However, little is known about systemic silver exposure and possible side effects. The aim of this study was to analyse serum silver concentrations in patients with silver-coated megaprostheses over a prolonged time period. Between 2004 and 2016, 46 patients (52.2% female, mean age at surgery 47.1 ± 24.2 years) received silver-coated megaprostheses for septic (n = 26) or oncological (n = 17; main implant since 2013) indications, or aseptic loosening (n = 3). Blood was drawn from all patients within the first few days following surgery (without silver ion levels) and thereafter every 6 months at the outpatient department (with silver ion levels). Inductively coupled plasma mass spectrometry was used to determine silver ion levels. Median follow-up was 47.3 months (IQR: 16.1-78.9). Overall, 29 revision surgeries became necessary in 20 patients, equivalent to a cumulative complication rate of 63.0%. Revisions were most commonly for periprosthetic joint infections (PJIs, n = 12) and instability/soft tissue problems (n = 10). Revision-free implant survival was 81.4%, 42.3% and 35.2% at one, 5 and 10 years. Incidence of local argyria was 8.7% (n = 4). Silver ion levels at two or more consecutive time points during follow-up were available for 26 patients. An increment of silver levels within the first months ("run-in") was observed, followed by an unspecific undulating course. Median initial and latest follow-up (median, 49.5 months) serum silver ion levels were 16.0 ppb (IQR: 9.1-29.1) and 7.4 ppb (IQR: 2.7-14.1), respectively. According to the multivariate mixed linear random-effects model, development of PJI was associated with significantly higher silver ion levels over time (p = 0.002), irrespective of time from surgery (p = 0.274). In the current series, a cumulative complication rate of 63.0% was observed for patients receiving silver-coated megaprostheses for septic of oncological indications. An overall unspecific course of silver ion concentration was present. Development of PJI was significantly associated with increased silver ion levels over time. Yet, no systemic complication associated to high silver levels occurred. It can be concluded that silver-coated implants constitute a safe solution for megaprosthetic reconstruction, but monitoring of silver concentrations is recommended.

Rice Intake, Arsenic Exposure, and Subclinical Cardiovascular Disease Among US Adults in MESA.

Background Arsenic-related cardiovascular effects at exposure levels below the US Environmental Protection Agency's standard of 10 µg/L are unclear. For these populations, food, especially rice, is a major source of exposure. We investigated associations of rice intake, a marker of arsenic exposure, with subclinical cardiovascular disease (CVD) markers in a multiethnic population. Methods and Results Between 2000 and 2002, MESA (Multi-Ethnic Study of Atherosclerosis) enrolled 6814 adults without clinical CVD. We included 5050 participants with baseline data on rice intake and markers of 3 CVD domains: inflammation (hsCRP [high-sensitivity C-reactive protein], interleukin-6, and fibrinogen), vascular function (aortic distensibility, carotid distensibility, and brachial flow-mediated dilation), and subclinical atherosclerosis at 3 vascular sites (carotid intima-media thickness, coronary artery calcification, and ankle-brachial index). We also evaluated endothelial-related biomarkers previously associated with arsenic. Rice intake was assessed by food frequency questionnaire. Urinary arsenic was measured in 310 participants. A total of 13% of participants consumed ≥1 serving of rice/day. Compared with individuals consuming <1 serving of rice/week, ≥1 serving of rice/day was not associated with subclinical markers after demographic, lifestyle, and CVD risk factor adjustment (eg, geometric mean ratio [95% CI] for hsCRP, 0.98 [0.86-1.11]; aortic distensibility, 0.99 [0.91-1.07]; and carotid intima-media thickness, 0.98 [0.91-1.06]). Associations with urinary arsenic were similar to those for rice intake. Conclusions Rice intake was not associated with subclinical CVD markers in a multiethnic US population. Research using urinary arsenic is needed to assess potential CVD effects of low-level arsenic exposure. Understanding the role of low-level arsenic as it relates to subclinical CVD may contribute to CVD prevention and control.

Arsenic exposure and hepatitis E virus infection during pregnancy.

BACKGROUND: Arsenic has immunomodulatory properties and may have the potential to alter susceptibility to infection in humans. OBJECTIVES: We aimed to assess the relation of arsenic exposure during pregnancy with immune function and hepatitis E virus (HEV) infection, defined as seroconversion during pregnancy and postpartum. METHODS: We assessed IgG seroconversion to HEV between 1st and 3rd trimester (TM) and 3 months postpartum (PP) among 1100 pregnancies in a multiple micronutrient supplementation trial in rural Bangladesh. Forty women seroconverted to HEV and were matched with 40 non-seroconverting women (controls) by age, parity and intervention. We assessed urinary inorganic arsenic plus methylated species (∑As) (µg/L) at 1st and 3rd TM and plasma cytokines (pg/mL) at 1st and 3rd TM and 3 months PP. RESULTS: HEV seroconverters' urinary ∑As was elevated throughout pregnancy. Non-seroconverters' urinary ∑As was similar to HEV seroconverters at 1st TM but declined at 3rd TM. The adjusted odds ratio (95% confidence interval) of HEV seroconversion was 2.17 (1.07, 4.39) per interquartile range (IQR) increase in average-pregnancy urinary ∑As. Increased urinary ∑As was associated with increased concentrations of IL-2 during the 1st and 3rd TM and 3 months PP among HEV seroconverters but not non-seroconverters. CONCLUSIONS: The relation of urinary arsenic during pregnancy with incident HEV seroconversion and with IL-2 levels among HEV-seroconverting pregnant women suggests arsenic exposure during pregnancy may enhance susceptibility to HEV infection.

Generalized indirect Fourier transformation as a valuable tool for the structural characterization of aqueous nanocrystalline cellulose suspensions by small angle X-ray scattering.

Small angle X-ray scattering (SAXS) is employed to characterize the inner structure and shape of aqueous nanocrystalline cellulose suspensions using the generalized indirect Fourier transformation (GIFT). The use of the GIFT approach provides a single fitting procedure for the determination of intra- and interparticle interactions due to a simultaneous treatment of the form factor P(q) and the structure factor S(q). Moreover, GIFT allows for the determination of particle charges and polydispersity indices. As test material, aqueous nanocrystalline cellulose suspensions (aNCS) prepared by the H2SO4 route have been investigated and characterized (SAXS, dynamic light scattering, zeta potential).

Evaluation of a novel standardized system for collection and quantification of oral fluid.

BACKGROUND: Standardization in collection and testing of oral fluid is lacking. METHODS: A novel standardized collection and quantification system for oral fluid testing was evaluated. Sample collection volumes were determined. For determination of the saliva content in oral fluid samples, tartrazine, which is an integral part of the saliva extraction solution serving as an internal standard, was used. Results were compared with those obtained by employing glucose as a 'supplemental internal standard' for determination. Analytical performance of the new system for collection and quantification of oral fluid was evaluated. Calcium and magnesium analyte concentrations in oral fluid samples were measured with a routine laboratory method and compared to a reference method. RESULTS: Volumes of oral fluid samples collected ranged from 4.9 to 10.5 mL. The mean saliva content in oral fluid samples was found to be 65.5 percent by volume (vol.-%) when determined through the tartrazine concentration and 65.0 vol.-% when determined through the glucose concentration. Evaluation of analytical performance revealed interassay imprecision coefficients of variation (CVs) ranging from 1.5% to 3.2% and intraassay imprecision CVs from 1.1% to 2.5%. When linearity was tested, a quasi-linear curve was observed (R2=0.99). Comparison of two different methods for determination of calcium and magnesium concentrations showed correlations of R2=0.96 for calcium and R2=0.97 for magnesium. CONCLUSIONS: The new system for collection and quantification of oral fluid helps to improve standardization of pre-analytics in oral fluid testing and to provide reliable and accurate quantification of analytes in oral fluid samples.