Comparison of Diatrizoate and Iohexol for Patient Acceptance and Fecal-Tagging Performance in Noncathartic CT Colonography.

OBJECTIVE: The aim of this study was to compare diatrizoate and iohexol regarding patient acceptance and fecal-tagging performance in noncathartic computed tomography colonography. METHODS: This study enrolled 284 volunteers with fecal tagging by either diatrizoate or iohexol at an iodine concentration of 13.33 mg/mL and an iodine load of 24 g. Patient acceptance was rated on a 4-point scale of gastrointestinal discomfort. Two gastrointestinal radiologists jointly analyzed image quality, fecal-tagging density and homogeneity, and residual contrast agent in the small intestine. The results were compared by the generalized estimating equation method. RESULTS: Patient acceptance was comparable between the 2 groups (3.95 ± 0.22 vs 3.96 ± 0.20, P = 0.777). The diatrizoate group had less residual fluid and stool than the iohexol group ( P = 0.019, P = 0.004, respectively). There was no significant difference in colorectal distention, residual fluid, and stool tagging quality between the 2 groups (all P 's > 0.05). The mean 2-dimensional image quality score was 4.59 ± 0.68 with diatrizoate and 3.60 ± 1.14 with iohexol ( P < 0.001). The attenuation of tagged feces was 581 ± 66 HU with diatrizoate and 1038 ± 117 HU with iohexol ( P < 0.001). Residual contrast agent in the small intestine was assessed at 55.3% and 62.3% for the diatrizoate group and iohexol group, respectively ( P = 0.003). CONCLUSIONS: Compared with iohexol, diatrizoate had better image quality, proper fecal-tagging density, and more homogeneous tagging along with comparable excellent patient acceptance, and might be more suitable for fecal tagging in noncathartic computed tomography colonography.

Disinfection byproducts of iopamidol, iohexol, diatrizoate and their distinct acute toxicity on Scenedesmus sp., Daphnia magna and Danio rerio.

The COVID-19 pandemic resulted in increasing the usage of iodinated contrast media (ICM), and thus an increase in the prevalence of ICM-contaminated wastewater. While ICM is generally safe, this has the potential to be problematic because as medical wastewater is treated and disinfected, various ICM-derived disinfection byproducts (DBPs) may be generated and released into the environment. However, little information was available about whether ICM-derived DBPs are toxic to aquatic organisms. In this study, the degradation of three typical ICM (iopamidol, iohexol, diatrizoate) at initial concentration of 10 µM and 100 µM in chlorination and peracetic acid without or with NH4+ was investigated, and the potential acute toxicity of treated disinfected water containing potential ICM-derived DBPs on Daphnia magna, Scenedesmus sp. and Danio rerio was tested. The degradation results suggested that only iopamidol was significantly degraded (level of degradation >98%) by chlorination, and the degradation rate of iohexol and diatrizoate were significantly increased in chlorination with NH4+. All three ICM were not degraded in peracetic acid. The toxicity analysis results indicate that only the disinfected water of iopamidol and iohexol by chlorination with NH4+ were toxic to at least one aquatic organism. These results highlighted that the potential ecological risk of ICM-contained medical wastewater by chlorination with NH4+ should not be neglected, and peracetic acid may be an environment-friendly alternative for the disinfection of wastewater containing ICM.

International Iohexol Shortage: Alternative Contrast Agents and Imaging Procedures for the Urologist.

INTRODUCTION: In April 2022, GE Healthcare announced a COVID-19-related interruption in iohexol manufacturing, leading to an international iodinated contrast shortage. The shortage greatly impacted urological practice, highlighting the value of alternative contrast agents and imaging/procedure alternatives. These alternatives are reviewed in this work. METHODS: A review of existing literature describing the use of alternative contrast agents, alternative imaging procedures, and contrast conservation strategies in urological care was performed using the PubMed database. The review was not performed systematically. RESULTS: Older iodinated contrast agents such as ioxaglate and diatrizoate can replace iohexol for intravascular imaging in patients without renal impairment. These agents, along with gadolinium-based agents such as Gadavist, have been used intraluminally for urological procedures and diagnostic imaging. Several lesser-known imaging and procedure alternatives are described and include air contrast pyelography, contrast-enhanced ultrasound, voiding urosonography, and low tube voltage CT urography. Conservation strategies include contrast dose reductions and use of contrast management devices for contrast vial splitting. CONCLUSIONS: The COVID-19-related iohexol shortage caused significant hardship for urological care internationally, leading to delayed contrasted imaging studies and urological procedures. Alternative contrast agents, imaging/procedure alternatives, and conservation strategies are reviewed in this work with the goal of equipping the urologist to mitigate the current iodinated contrast shortage and to prepare in the event of a future shortage.

Modification and evaluation of diatrizoate sodium containing polymethyl methacrylate bone cement.

Polymethyl methacrylate (PMMA) bone cement is now widely used in percutaneous vertebro plasty (PVP) and percutaneous kyphoplasty (PKP). However, studies showed that the radiopacifiers (zirconia, barium sulfate, etc.) added to PMMA will have a negative impact on its use, e.g. barium sulfate will weaken the mechanical properties of bone cement and lead to bone absorption and aseptic loosening. Iodine is an element existing in the human body and has good imaging performance. Iodine contrast agent has been used in clinic for many years and has abundant clinical data. Therefore, using iodine instead of barium sulfate may be a promising choice. In this paper, the effect of different content of diatrizoate sodium (DTA, C11H8I3N2NaO4) on the properties of PMMA was studied and compared with the traditional PMMA bone cement containing 30 wt% barium sulfate. The mechanical properties, setting properties, radiopacity, and biocompatibility of bone cement were evaluated. The compressive strength of PMMA bone cement with 20 wt% DTA can reach 76.38 MPa. DTA released from bone cement up to 14 days accounted for only 2.3% of its dosage. The water contact angle was 62.3°. The contrast of bone cement on X-ray film was comparable to that of bone cement containing 30 wt% barium. The hemolysis rate was lower than 4%, and there was no obvious hemolysis. PMMA with 20 wt% DTA can maintain the relative growth rate of MC3T3-E1 and L929 cells above 80%. The results show that adding 20 wt% DTA into PMMA can obtain good radiopacity while maintaining its mechanical properties, setting properties, and biocompatibility. DTA can be used as a promising candidate material for PMMA bone cement radiopacifier.

Evaluation of the accumulation of the iodinated contrast agents diatrizoic acid and iohexol in Dreissena polymorpha mollusks.

Mollusks are very sensitive to aquatic environmental alterations and then, are important bio-indicators for monitoring the contamination of water bodies. Iodinated X-ray contrast media (ICMs) are ubiquitously present in the aquatic environment, primarily due to their high consumption for diagnosis purposes, high injection levels, low biodegradability, and low removal rates by wastewater treatment plants. Although these compounds are assumed to be of low toxicity, aquatic organisms are continuously exposed to these agents, which may result in adverse effects as ICMs can act as iodine source and disrupt the endocrine system. Thus, the evaluation of their environmental risk, especially on aquatic fauna is of great interest. To this end, we first compared the accumulation behavior, based on iodine analysis, of two ICM exhibiting different osmolality, diatrizoic acid and iohexol in Dreissena polymorpha bivalves exposed under laboratory conditions at concentrations of 0, 100, and 1000 µg/L during 4 and 7 days. This study was the first to provide information on iodine concentration in whole soft tissues and several organs in control zebra mussels. Moreover, it showed, after exposure, an increase of iodine content mainly in the digestive glands, followed by gills and gonads, highlighting that ICMs actually enter the organisms. Thus, bioaccumulation of ICMs studies were then performed, by liquid chromatography coupled to tandem mass spectrometry, on entire mollusks and digestive glands of organisms exposed at 0, 10, 100, and 1000 µg/L of both ICMs during 21 days, followed by 4 days of depuration. These first data on ICMs concentrations in zebra mussels, showed a clear accumulation of ICMs in mussels as a function of relative exposure level, as well as a rapid depuration. Osmolality did not seem to have a significant impact on the accumulation level, but a slight difference was observed on the accumulation pattern between both ICMs.

Assessing the skin irritation and sensitizing potential of concentrates of water chlorinated in the presence of iodinated X-ray contrast media.

Chemical disinfection of water provides significant public health benefits. However, disinfectants like chlorine can react with naturally occurring materials in the water to form disinfection byproducts (DBPs). Natural levels of iodine have been reported to be too low in some source waters to account for the levels of iodinated DBPs detected. Iodinated X-ray contrast media (ICM) have been identified as a potential source of iodine. The toxicological impact of ICM present in source water at the time of disinfection has not been fully investigated. Iopamidol, iohexol, iopromide, and diatrizoate are among the ICM most frequently detected in water. In this study, source water containing one of these four ICM was chlorinated; non-chlorinated ICM-containing water samples served as controls. Reactions were conducted at an ICM concentration of 5 µM and a chlorine dose of 100 µM over 72 hr. Water concentrates (20,000-fold) were prepared by XAD-resin/ethyl acetate extraction and DMSO solvent exchange. We used the MatTek® reconstituted human epithelial skin irritation model to evaluate the water concentrates and also assessed the dermal irritation and sensitization potential of these concentrates using the LLNA:BrdU ELISA in BALB/c mice. None of the water concentrates tested (2500X) resulted in a skin irritant response in the MatTek® skin irritation model. Likewise, none of the concentrates (2500X, 1250X, 625X, 312.5X, 156.25X) produced a skin irritation response in mice: erythema was minimal; the maximum increase in ear thickness was less than 25%. Importantly, none of the concentrates produced a positive threshold response for allergic skin sensitization at any concentration tested in the LLNA:BrdU ELISA. We conclude that concentrates of water disinfected in the presence of four different ICM did not cause significant skin irritation or effects consistent with skin sensitization at the concentrations tested.

[Studies on the use of iodine-containing contrast agent diatrizoate in rabbits (Oryctolagus cuniculus)]. / Untersuchungen zum Einsatz des jodhaltigen Kontrastmittels Amidotrizoesäure beim Kaninchen (Oryctolagus cuniculus).

OBJECTIVE: The use of the iodine-containing contrast agent diatrizoate was investigated in healthy rabbits and in rabbits with gastric dilatation and intestinal obstruction. For this purpose, transit times through the gastrointestinal tract and clinical use were investigated during a one year period. In addition, a possible influence on thyroid hormone levels was evaluated. MATERIAL AND METHODS: Transit times of contrast agent through the different intestinal sections were examined radiographically in 14 healthy rabbits. For this purpose, 7 ml/kg of a 300 mg iodine/ml and 600 mg diatrizoate/ml containing solution were administered. Radiographs were obtained at different time intervals. Three different doses (D1 2 ml/kg, D2 7 ml/kg, D3 10 ml/kg) were administered, and blood samples were collected at two time points (60 min, 24 h) to analyze thyroid hormone levels (TT4, fT4, TSH). In addition, 70 rabbits that had received the contrast agent diatrizoate because of gastric dilatation and suspected intestinal obstruction were retrospectively evaluated during a period of one year. Focus was placed on arrival of the contrast agent in the cecum, laboratory changes, and mortalities. RESULTS: In all healthy rabbits, contrast medium was detectable in the cecum after a mean of 45-60 min. In the animals suffering from gastrointestinal obstruction, this was delayed to a mean of 121.2 min. These animals showed hypothermia in 92.4 % and hyperglycemia in 45.9 %. 56.1 % exhibited an increase in urea and 33.9 % an increase in creatinine. In 71.4 % of cases, medical treatment was possible, however 12 % of these individuals succumbed to the disease. 28.6 % of the cases were managed surgically which was associated with a mortality of 50 %. TT4, fT4, and TSH levels displayed significant alterations among the three contrast agent doses (p < 0.05). These changes were found to be transient when follow-up was performed two weeks later. CONCLUSION AND CLINICAL RELEVANCE: When ileus is suspected in rabbits, diatrizoate may be helpful in evaluating the progression of the disease in addition to the use of native radiographs. Sufficient hydration and monitoring of renal function are advisable. Transient changes in thyroid hormones were evident but lacked clinical relevance.

The effectiveness and biosafety of diatrizoate contrast media in complicated cholelithiasis.

Adverse reactions after intravascular administration of iodine-based contrast media are well-known. Nevertheless the same type of contrast media is also used for endoscopic retrograde cholangiopancreatography and systemic absorption of contrast media after mentioned procedure routinely occurs, not much is known about effects of widely used diatrizoates (Triombrast) on the hepato-pancreato-biliary system in case of cholelithiasis treatment. AIM: The aim of the present study was to determine the effectiveness and biosafety of diatrizoate contrast media in terms of complicated cholelithiasis healing using conventional and improved surgery treatment protocols based on set of biochemical markers. MATERIALS AND METHODS: The paper presents materials of clinical observation and biochemical analysis of 122 patients have been diagnosed with gallstone disease complicated by choledocholithiasis and cholangitis and biliary pancreatitis. Biochemical liver tests before and after surgery treatment using conventional and improved protocols were determined. RESULTS: Biochemical manifestations of hepatocellular injury included exceeded activity of γ-glutamyltranspeptidase and aminotrasferases as well as level of liver fatty acid-binding protein and bilirubin which were different between groups of patients with cholelithiasis who suffered from concomitant cholangitis and pancreatitis. Proposed management algorithm for patients with gallstone disease with concomitant cholangitis and pancreatitis links to get rid of endoscopic retrograde cholangiography with contrast agent from the conventional surgery treatment protocols because its most obvious downside. CONCLUSIONS: Patients with gallstone diseases revealed significant biochemical changes that should be successfully resolved after surgery treatment without endoscopic retrograde cholangio- pancreatography with contrast media because its hepatotoxic effect.

Diatrizoate (Gastrograffin®) Small Bowel Follow Through for Small Bowel Obstructions: Timing and Outcomes.

INTRODUCTION: The advent of the Gastrograffin® small bowel follow through (G-SBFT) has resulted in a decreased rate of operative intervention of small bowel obstructions (SBO); however, there is no data to suggest when G-SBFT should be performed. METHODS: We retrospectively reviewed 548 patients, admitted to 1 of 9 hospitals with a diagnosis of SBO. Patients were divided into two categories with regards to timing of G-SBFT: before (early) or after (late) 48 hours from admission. Primary outcomes were length of stay (LOS) and total cost. Secondary outcomes were operative interventions and mortality. RESULTS: Of the reviewed patients, 71% had the G-SBFT ordered early. Comparing early versus late, there were no differences in patient characteristics with regards to age, sex, or BMI. There was a significant difference between LOS (4 vs 8 days, P < 0.05) and total cost ($17,056.19 vs $33,292.00, P < 0.05). There was no difference in mortality (1.3% vs 2.6%, P = 0.239) or 30-day readmission rates (15.6% vs 15.9%, P = 0.509). Patients in the early group underwent fewer operations (20.7% vs 31.9%, P = 0.05). DISCUSSION: Patients that had a G-SBFT ordered early had a decreased LOS, total cost, and operative intervention. This suggests there is a benefit to ordering G-SBFT earlier in the hospital stay to reduce the overall disease burden, and that it is safe to do so with regards to mortality and readmissions. We therefore recommend ordering a G-SBFT within 48 hours to reduce LOS, cost, and need for an operation.

Thiourea Dioxide Coupled with Trace Cu(II): An Effective Process for the Reductive Degradation of Diatrizoate.

Diatrizoate, a refractory ionic iodinated X-ray contrast media (ICM) compound, cannot be efficiently degraded in a complex wastewater matrix even by advanced oxidation processes. We report in this research that a homogeneous process, thiourea dioxide (TDO) coupled with trace Cu(II) (several micromoles, ubiquitous in some wastewater), is effective for reductive deiodination and degradation of diatrizoate at neutral pH values. Specifically, the molar ratio of iodide released to TDO consumed reached 2 under ideal experimental conditions. TDO eventually decomposed into urea and sulfite/sulfate. Based on the results of diatrizoate degradation, TDO decomposition, and Cu(I) generation and consumption during the TDO-Cu(II) reaction, we confirmed that Cu(I) is responsible for diatrizoate degradation. However, free Cu(I) alone did not work. It was proposed that Cu(I) complexes are actual reactive species toward diatrizoate. Inorganic anions and effluent organic matter negatively influence diatrizoate degradation, but by increasing the TDO dosage, as well as extending the reaction time, its degradation efficiency can still be guaranteed for real hospital wastewater. This reduction reaction could be potentially useful for in situ deiodination and degradation of diatrizoate in hospital wastewater before discharge into municipal sewage networks.

T cell mediated hypersensitivity to previously tolerated iodinated contrast media precipitated by introduction of atezolizumab.

Many adverse reactions associated with immune checkpoint inhibitor (ICI) treatments are immunologically driven and may necessitate discontinuation of the ICI. Herein, we present a patient who had been administered the radio contrast media amidotrizoate multiple times without issue but who then developed a Stevens-Johnson syndrome reaction after coadministration of atezolizumab. Causality was confirmed by a positive re-challenge with amidotrizoate and laboratory investigations that implicated T cells. Importantly, the introduction of atezolizumab appears to have altered the immunologic response to amidotrizoate in terms of the tolerance-elicitation continuum. Proof of concept studies demonstrated enhancement of recall responses to a surrogate antigen panel following in-vitro (healthy donors) and in-vivo (ICI patients) administrations of ICIs. Our findings highlight the importance of considering all concomitant medications in patients on ICIs who develop immune-mediated adverse reactions. In the event of some immune-related adverse reactions, it may be critical to identify the culprit antigen-forming entity that the ICIs have altered the perception of rather than simply attribute causality to the ICI itself in order to optimize both patient safety and treatment of malignancies.

Unexpected degradation and deiodination of diatrizoate by the Cu(II)/S(IV) system under anaerobic conditions.

Transition metal catalyzed sulfite auto-oxidation is a promising technology used in water and wastewater treatment for the elimination of contaminants. In the literature, this process has been reported to be efficient only in the presence of oxygen. However, in this study, we unexpectedly found that the degradation of diatrizoate (DTZ) by a system based on the combination of copper ion and sulfite (Cu(II)/S(IV)) reached over 95% under anaerobic conditions, but was considerably retarded under aerobic conditions at pH 7. Furthermore, it was found that Cu(I), generated from the cleavage of the CuSO3 complex, was the main reactive species responsible for the degradation of DTZ by the Cu(II)/S(IV) system under anaerobic conditions. In fact, the absence of oxygen promoted the accumulation of Cu(I). The concomitant release of the iodide ion with the degradation of DTZ indicated that the anaerobic degradation of DTZ by the Cu(II)/S(IV) system mainly proceeded through the deiodination pathway, which was also confirmed by the detection of deiodinated products. The anaerobic degradation of DTZ was favored at higher initial concentrations of Cu(II) or sulfite in this system. Since the CuSO3 complex, the precursor of Cu(I), was formed mainly at pH 7, the highest anaerobic degradation of DTZ was achieved at pH 7. An increase in reaction temperature considerably enhanced the degradation of DTZ by the Cu(II)/S(IV) system with an apparent activation energy of 119.4 kJ/mol. The presence of chloride, bicarbonate and humic acid slightly influenced the anaerobic degradation of DTZ. The experiments with real water samples also demonstrated the effectiveness of the degradation of DTZ by the Cu(II)/S(IV) system under anaerobic conditions.

A direct injection liquid chromatography tandem mass spectrometry method for the kinetic study on iodinated contrast media (ICMs) removal in natural water.

Iodinated contrast media (ICMs) are a class of X-ray contrast media worldwide utilized for radiographic procedures. Since they cannot be removed efficiently during water treatment, they can be found in surface and groundwater. In this work, a rapid and sensitive direct injection liquid chromatography-tandem (LC-MS/MS) method for the simultaneous analysis of seven ICMs media (iopamidol, ioxitalamic acid, diatrizoic acid, iothalamic acid, iohexol, iomeprol and iopromide) in complex aqueous matrices has been developed and validated. The MDLs for the analytes ranged from 0.7 to 21 ng L-1 in ultrapure water, and recoveries ranged from 86 to 100% in drinking water, 85-103% in groundwater and 84-105% in WWTP effluent. A stereo-isomer for iopromide was separated. This analytic method was applied to investigate the removal of target ICMs by low pressure ultra violet light (LPUV) advanced oxidation processes with three oxidants, hydrogen peroxide, free chlorine and monochloramine in groundwater. Results showed that the addition of oxidants did not enhance attenuation of ICMs, since fluence-based decay apparent rate constants were similar (KUV = 3.2 × 10-3, KUV-Cl2 = 3.6 × 10-3 and KUV-NH2 = 3.4 × 10-3 10-3 cm2 mJ-1). This yielded direct photolysis is the main mechanism to attenuate target ICMs.

Positive Oral Contrast Solution at MDCT for Suspected Acute Appendicitis in Adults: Rate of Appendiceal Luminal Filling of Normal and Inflamed Appendixes.

OBJECTIVE. The purpose of this study was to assess the rate of appendiceal filling with a positive oral contrast solution at MDCT performed for suspected acute appendicitis in adults. MATERIALS AND METHODS. We performed a retrospective review of MDCT in 684 consecutive adult patients with suspected acute appendicitis in a 19-month period. Patients were excluded if no positive oral contrast solution (500 mL each of water and polyethylene glycol and 30 mL diatrizoate) was given or if the appendix was not visible or absent. After exclusion, images of 519 patients (mean age ± SD, 37.4 ± 16.0 years; 335 women, 184 men) were reviewed for cecal contrast opacification and appendiceal filling. Imaging findings were recorded as positive or negative for acute appendicitis using all available clinical and pathologic data as a reference standard. A control series of CT colonography (CTC) screening examinations (overnight preparation with universal cecal opacification) in 2552 adults without symptoms of appendicitis was also reviewed. RESULTS. Cecal opacification was confirmed in 313/519 (60.3%) patients, with no difference between those considered to be positive (68/107, 63.6%) or negative (245/412, 59.5%) for appendicitis (p = 0.506). When positive oral contrast solution reached the cecum, appendiceal filling was seen in none of the 68 (0%) with appendicitis and in 205 of the 245 (83.7%) without appendicitis (p < 0.0001). Among CTC control subjects, appendiceal filling was similar to the cohort considered to be without appendicitis (2240/2552 [87.8%], p = 0.070). CONCLUSION. In MDCT for suspected acute appendicitis, luminal filling of the noninflamed appendix exceeds 80% when positive oral contrast solution reaches the cecum, indicating results similar to screening CTC. The appendix did not fill in proven acute appendicitis, indicating appendiceal filling may allow exclusion of appendicitis with high certainty. These results suggest positive oral contrast solution may augment diagnostic accuracy and confidence in cases of suspected acute appendicitis.

Radiocontrast Agent Diatrizoic Acid Induces Mitophagy and Oxidative Stress via Calcium Dysregulation.

Contrast-induced acute kidney injury (CI-AKI) is the third most common cause of hospital associated kidney damage. Potential mechanisms of CI-AKI may involve diminished renal hemodynamics, inflammatory responses, and direct cytotoxicity. The hypothesis for this study is that diatrizoic acid (DA) induces direct cytotoxicity to human proximal tubule (HK-2) cells via calcium dysregulation, mitochondrial dysfunction, and oxidative stress. HK-2 cells were exposed to 0-30 mg I/mL DA or vehicle for 2-24 h. Conversion of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and trypan blue exclusion indicated a decrease in mitochondrial and cell viability within 2 and 24 h, respectively. Mitochondrial dysfunction was apparent within 8 h post exposure to 15 mg I/mL DA as shown by Seahorse XF cell mito and Glycolysis Stress tests. Mitophagy was increased at 8 h by 15 mg I/mL DA as confirmed by elevated LC3BII/I expression ratio. HK-2 cells pretreated with calcium level modulators BAPTA-AM, EGTA, or 2-aminophenyl borinate abrogated DA-induced mitochondrial damage. DA increased oxidative stress biomarkers of protein carbonylation and 4-hydroxynonenol (4HNE) adduct formation. Caspase 3 and 12 activation was induced by DA compared to vehicle at 24 h. These studies indicate that clinically relevant concentrations of DA impair HK-2 cells by dysregulating calcium, inducing mitochondrial turnover and oxidative stress, and activating apoptosis.

Ultrasensitive Fluorescence Detection of Alzheimer's Disease Based on Polyvalent Directed Peptide Polymer Coupled to a Nanoporous ZnO Nanoplatform.

Amyloid-beta 42 (Aß42), the key biomarker of Alzheimer's disease (AD), aggregates to form neurotoxic amyloid plaques. In this work, we modified two fluorescein isothiocyanate-labeled Aß42-targeting peptides and designed an Aß42-specific ultrasensitive polyvalent-directed peptide polymer (PDPP) to enhance AD diagnosis sensitivity. The dissociation constant of Aß42 by PDPP was 103-fold higher than the single-site-directed peptide. The improved binding was due to the ability of PDPP to detect multiple receptors on the target. The power of the PDPP diagnostic probe was verified in its application to detect Aß42 in cerebrospinal fluid (CSF), which showed a lower limit of detection (LOD) in the fg mL-1 range that is more sensitive than detection by antibodies or single peptides. In addition, we present a novel ultrasensitive diagnostic system using an array of nanoporous ZnO nanoparticles, which play a role in fluorescence signal amplification, to further improve AD diagnosis sensitivity. We enhanced the signal on the basis of the properties of nanoporous ZnO nanoparticles and measured and quantified an ultralow concentration (ag mL-1 range) of Aß42. This PDPP coupled to the nanoporous ZnO-based system is a novel approach to AD diagnosis that might also be useful for the detection of other target biomarkers and clinical applications.

Abiotic reductive deiodination of iodinated organic compounds and X-ray contrast media catalyzed by free corrinoids.

Iodinated X-ray contrast media are known for their stability concerning deiodination in the aquatic environment under aerobic conditions. In this study, we demonstrate the abiotic reductive deiodination of the iodinated contrast media iopromide, iopamidol and diatrizoate in the presence of corrinoids. In addition, triiodinated benzoic acid derivatives with iodine atoms bound at different positions were investigated. Corrinoids like cyanocobalamin (vitamin B12) and dicyanocobinamide served as electron shuttles and as catalysts between the reducing agent (e.g., titanium (III) citrate) and the electron accepting iodinated compound. The concentration decrease of the iodinated compounds followed first-order kinetics with rate constant kobs depending on the iodinated compound. A linear correlation between the rate of iodide release and the corrinoid concentration was observed, with deiodination rates for dicyanocobinamide twice as high as for vitamin B12. Reducing agents with a less negative standard redox potential like dithiothreitol or cysteine caused slower deiodination as the cobalt center was only reduced to its CoII oxidation state. With a temperature increase from 11 to 23 °C, the concentrations of released iodide doubled. A complete deiodination was only observed for the iodinated contrast media but not for structurally similar iodinated benzoic acid derivatives.

Detection of artificial sweeteners and iodinated X-ray contrast media in wastewater via LC-MS/MS and their potential use as anthropogenic tracers in flowing waters.

The detection of wastewater impact on stream chemistry is often hindered by high background concentrations of ubiquitous solutes. In the present study we tested the applicability of artificial sweeteners (AS) and iodinated X-ray contrast media (ICM) as tracers to detect this impact by examining wastewater treatment plant (WWTP) effluents and surface water samples. The developed direct injection LC-MS/MS method enabled the detection of these anthropogenic micropollutants in aqueous samples down to trace level concentrations. The 2-h-composite sampling of WWTP effluent revealed fluctuating ICM concentrations between and within days with highest concentrations at the end of the week. Diatrizoic acid (DTZ) and iopromide (IOP) were the predominant ICM with concentrations up to 7 µg/L. Concentrations of the AS acesulfame (ACE) fluctuated between 0.5 µg/L and 1 µg/L. Concentrations of AS and ICM in surface water were both associated with wastewater impact. DTZ contamination was more widespread whereas some sampling points exhibited a more pronounced contamination with non-ionic ICM. Surface water was frequently contaminated with AS. Particularly ACE was detected in every surface water sample indicating that it is chemically stable and that inputs to the aquatic environment via WWTP effluents are widespread. The broad application of ACE as food additive enables its application as a tracer throughout Germany. Furthermore, the developed LC-MS/MS method enables rapid detection of ACE down to the low ng/L-range. Nonetheless, DTZ or IOP could be used in addition to ACE to verify anthropogenic influences on natural waters.

Radiologic assessment of gastric emptying of water-soluble contrast media: New data security from a longitudinal study. / Evaluación radiológica del vaciamiento gástrico de medio de contraste hidrosoluble: nuevos datos de seguridad de un estudio longitudinal.

BACKGROUND AND OBJECTIVES: Practice guidelines for preoperative fasting have not clearly established the fasting time needed after oral administration of water-soluble contrast media. The aim of this study was to determine the time required for the gastric emptying during the water-soluble contrast media in patients with acute abdominal pain. METHODS: This prospective longitudinal study included sixty-eight patients older than 18 years of age with acute abdominal pain, who required a water-soluble contrast media enhanced abdominal computed tomography study. Plain radiographs were obtained hourly until complete the gastric emptying. Patients with probable bowel obstruction were not included in the study. RESULTS: A total of 31 (45,6%), 54 (79,4%), and 64 (94,1%) patients achieved a complete gastric clearance of barium in 1, 2 and 3 hours, respectively. All patients achieved complete emptying of water-soluble contrast media within 6 hours. Gastric emptying time was not associated with gender (P=0,44), body mass index (P=.35), fasting time prior to water-soluble contrast media intake (P=0,12), administration of opioids in the emergency room (P=0,7), and the presence of comorbidities (P=0,36). CONCLUSION: Ninety-four percent of the patients with acute abdominal pain achieved complete gastric emptying within 3hours after the administration of water-soluble contrast media. All of them achieved complete gastric emptying within 6hours. The results suggested 6hours after oral intake of the contrast media is enough to complete transit of water-soluble contrast media through the stomach and avoid unnecessary risks.

Catalytic Degradation of Diatrizoate by Persulfate Activation with Peanut Shell Biochar-Supported Nano Zero-Valent Iron in Aqueous Solution.

An emerging pollutant, diatrizoate (DTZ) has been frequently detected in aqueous solution. Unique reticular peanut shell biochar (BC)-supported nano zero-valent iron (nZVI) composite (nZVI/BC) was successfully synthesized and used as a catalyst for activating persulfate (PS) to promote the removal of DTZ. The structure and morphology of the nanocomposite materials were characterized by scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller measurements, and Fourier transform infrared spectroscopy. The degradation of DTZ (20 mg L-1) was achieved by activating PS with the nanocomposite material. The removal of DTZ reached nearly 100% using 25 mM PS and 0.45 g L-1 nZVI/2BC (mass ratio of nZVI and BC at 1:2) nanocomposite material at pH 3.0 and 25 °C. Influencing factors, such as dosages of nZVI/2BC and PS, temperature, and pH were also investigated. The mechanisms of PS activation with nZVI/2BC were discussed, including BC property, electron transfer, and the identification of free radicals in the reaction. The findings demonstrated that nZVI/BC-PS (peanut shell BC-supported nZVI activating PS) is a promising material for the treatment of refractory organic pollutants.