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Iodixanol is an iso-osmolar non-ionic dimeric hydrophilic contrast agent with a higher viscosity than the monomeric agents. It is the only Food and Drug Administration (FDA)-approved iso-osmolar agent in the United States, and it is the only contrast agent with an FDA-approved indication for use in cardiac computed tomographic angiography (CCTA), to assist in the diagnostic evaluation of patients with suspected coronary artery disease. In clinical studies, it has been noted to have fewer side effects and similar image quality when compared to low-osmolar contrast media. This can be attributed to the pharmacological properties of iodixanol. These contrast agents are used for coronary computed tomography angiography and cardiac catheterization. In this article, the use, tolerability, and efficacy of iodixanol are reviewed, specifically evaluating the use of CCTA and coronary angiography, including outcome studies, randomized trials, and comparisons to other contrast agents.

This article develops a multi-perspective view on motivations and methods for tobamovirus purification through the ages and presents a novel, efficient, easy-to-use approach that can be well-adapted to different species of native and functionalized virions. We survey the various driving forces prompting researchers to enrich tobamoviruses, from the search for the causative agents of mosaic diseases in plants to their increasing recognition as versatile nanocarriers in biomedical and engineering applications. The best practices and rarely applied options for the serial processing steps required for successful isolation of tobamoviruses are then reviewed. Adaptations for distinct particle species, pitfalls, and 'forgotten' or underrepresented technologies are considered as well. The article is topped off with our own development of a method for virion preparation, rooted in historical protocols. It combines selective re-solubilization of polyethylene glycol (PEG) virion raw precipitates with density step gradient centrifugation in biocompatible iodixanol formulations, yielding ready-to-use particle suspensions. This newly established protocol and some considerations for perhaps worthwhile further developments could serve as putative stepping stones towards preparation procedures appropriate for routine practical uses of these multivalent soft-matter nanorods. [ABSTRACT FROM AUTHOR]

Yang Zhao,1 Hua Wang,2 Zhengjun Wu,1 Yunxiang Zhu,1 Jingsong Wang1 1Department of Pharmacy, Guangyuan Central Hospital, Guangyuan, Sichuan, People’s Republic of China; 2Department of Neurosurgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of ChinaCorrespondence: Jingsong Wang, Department of Pharmacy, Guangyuan Central Hospital, Guangyuan, Sichuan, People’s Republic of China, Email wjs5515@163.comBackground: Adverse reactions induced by isoosmolar contrast medium (iodixanol) are mostly mild, with rashes and headaches being the most common. Although anaphylactic shock has been reported, no related incidents have been documented on cerebral angiography.Objective: This article reports a serious case of anaphylactic shock possibly induced by iodixanol and provides an overview of the case report.Case Summary: A 65-year-old female with persistent headaches for nearly six months and CTA examination revealed multiple intracranial aneurysms. After two treatments, she returned to the hospital for aneurysm of reexamination a month ago. Following a preoperative assessment, cerebral angiography was performed. Three minutes after the procedure, the patient experienced dizziness, increased heart rate, followed by hypotension (BP 90/43 mm Hg), a sudden drop-in heart rate (HR 68 bpm), and a drop in SpO2 to 92%. Intravenous dexamethasone for anti-allergic were administered immediately, along with therapy through oxygen-inhalation. However, the patient then developed limb convulsions, unresponsiveness, and was urgently given diazepam for sedation and sputum aspiration to maintain airway patency. Blood pressure decrease to 53/29 mm Hg, and SpO2 readings were unavailable. Intravenous dopamine to elevates blood pressure, and assists breathing by intubating in the endotracheal. After 3 minutes, as the blood pressure remained undetectable, intermittent intravenous epinephrine 1mg was administered to raise the blood pressure, gradually restoring it to 126/90 mm Hg, and SpO2 increased to 95%. The patient was diagnosed with iodixanol-induced anaphylactic shock and urgently transferred to the NICU for monitoring and treatment. The patient died despite immediate treatment.Conclusion: A 65-year-old female developed serious anaphylactic shock during cerebral angiography after receiving iodixanol. Although iodixanol is considered one of the safest iodinated contrast mediums (ICM), clinicians should be aware of its the potential for serious hypersensitivity reactions that can lead to fatal and life-threatening events.Keywords: iodixanol, cerebral angiography, hypersensitivity reaction, anaphylactic shock

Objective: This study aimed to explore the signal detection method for allergic reactions induced by inpatient iodixanol injection. Methods: A database of 3,719,217 hospitalized patients from 20 large Chinese general hospitals was processed and analyzed using the prescription sequence symmetry analysis (PSSA) method. Results: 126,680 inpatients who used iodixanol and were concurrently treated with anti-allergic drugs were analyzed. In the medical records of these patients, only 32 had documented iodixanol allergies. Statistical analysis identified 22 drugs in 4 categories--calcium preparations, adrenergic/dopaminergic agents, glucocorticoids, and antihistamines--as marker drugs. With time intervals of 3, 7, and 28 days, the adjusted sequence ratios (aSRs) for all anti-allergics and the 4 categories were greater than 1. The 7-day aSRs were 2.12 (95% CI: 2.08-2.15), 1.70 (95% CI: 1.68-1.73), 3.85 (95% confidence interval [CI]: 3.75-2.30), 2.30 (95% CI: 2.26-2.35), and 1.95 (95% CI: 1.89-2.02), respectively. The proportions of adverse drug events indicated by each signal were as follows: all anti-allergics (2.92%-3%), calcium gluconate (0.19%-0.52%), adrenergic/dopaminergic agents (2.20%-3.37%), glucocorticoids (3.13%-3.76%), and antihistamines (1.05%-1.32%). Conclusion: This first multi-center Chinese inpatient database study detected iodixanol-induced allergy signals, revealing that reactions may be much higher than those in collected spontaneous reports. Iodixanol risk exposure was closer to actual pharmaceutical care findings. PSSA application with =7-day intervals appears better suited for monitoring late allergic reaction signals with these drugs. [ABSTRACT FROM AUTHOR]

Objective:This study aimed to explore the signal detection method for allergic reactions induced by inpatient iodixanol injection.Methods:A database of 3,719,217 hospitalized patients from 20 large Chinese general hospitals was processed and analyzed using the prescription sequence symmetry analysis (PSSA) method.Results:126,680 inpatients who used iodixanol and were concurrently treated with anti-allergic drugs were analyzed. In the medical records of these patients, only 32 had documented iodixanol allergies. Statistical analysis identified 22 drugs in 4 categories—calcium preparations, adrenergic/dopaminergic agents, glucocorticoids, and antihistamines—as marker drugs. With time intervals of 3, 7, and 28 days, the adjusted sequence ratios (aSRs) for all anti-allergics and the 4 categories were greater than 1. The 7-day aSRs were 2.12 (95% CI: 2.08–2.15), 1.70 (95% CI: 1.68–1.73), 3.85 (95% confidence interval [CI]: 3.75–2.30), 2.30 (95% CI: 2.26–2.35), and 1.95 (95% CI: 1.89–2.02), respectively. The proportions of adverse drug events indicated by each signal were as follows: all anti-allergics (2.92%–3%), calcium gluconate (0.19%–0.52%), adrenergic/dopaminergic agents (2.20%–3.37%), glucocorticoids (3.13%–3.76%), and antihistamines (1.05%–1.32%).Conclusion:This first multi-center Chinese inpatient database study detected iodixanol-induced allergy signals, revealing that reactions may be much higher than those in collected spontaneous reports. Iodixanol risk exposure was closer to actual pharmaceutical care findings. PSSA application with ≤7-day intervals appears better suited for monitoring late allergic reaction signals with these drugs.

This study was conducted to evaluate the effect of the comparative study of contrast media for gastrography of the mynah bird. This study was conducted on 12 adult male mynah birds. Using different contrast agents, all the birds were studied five times, with a minimum of two days of the time interval between each study. Radiographic tests were performed 1, 5, 15, 30, 60, and 90 minutes after ingesting the contrast agent via using a gavage tract; imaging was performed at a time interval of 30 minutes and continued until the time when the contrast agent reached the cloaca and was excreted. There was a statistically significant difference between the results of digestive system studies using Iodixanol, Iohexol, and barium sulfate in terms of mean scores of the contrast agent’s ability to fill different parts of the gastrointestinal tract, clarity of observations, and observing details of the gastrointestinal tract at all times of radiography (p < 0.05). Iodixanol is less nephrotoxic and is a better contrast agent, however, we do not recommend using Iodixanol and Iohexol diluted by water at a ratio of 1:1.

To study the effect of non-ionic contrast media on anticoagulated and non-anticoagulated human whole blood samples, calorimetric measurements were performed. The anticoagulated plasma showed the greatest fall in the total ΔH after Iodixanol treatment. The plasma-free erythrocytes revealed a pronounced shift in the Tmax and a decrease in the ΔH of hemoglobin and transferrin. The total ΔH of Iodixanol treatment showed the highest decline, while Iomeprol and Iobitridol had fewer adverse effects. Similarly, the non-anticoagulated samples revealed a decrease both in the Tmax and the ΔH of albumin and immunoglobulin-specific transitions. The total ΔH showed that Iodixanol had more influence on the serum. The serum-free erythrocyte samples resulted in a significant drop in the Tmax of erythrocyte and transferrin (~5–6 °C). The ΔH of deconvolved hemoglobin and transferrin decreased considerably; however, the ΔH of albumin increased. Surprisingly, compared to Iomeprol and Iobitridol treatments, the total ΔH of Iodixanol was less pronounced in the non-anticoagulated erythrocyte samples. In sum, each non-ionic contrast medium affected the thermal stability of anticoagulated and non-anticoagulated erythrocyte proteins. Interestingly, Iodixanol treatment caused more significant effects. These findings suggest that conformational changes in blood components can occur, which can potentially lead to the increased prevalence of cardiovascular dysfunctions and blood clotting. [ABSTRACT FROM AUTHOR]

Lin Qiu, Qihao Cui, Xuepeng Gong, Haiyun Zhou Department of Pharmacy, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People’s Republic of ChinaCorrespondence: Haiyun Zhou, Department of Pharmacy, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Avenue, Wuhan, 430030, People’s Republic of China, Email haiyunzhou426@126.comBackground: Iodixanol-induced anaphylactic reaction is a well-known adverse event of contrast agents, which are generally well-tolerated and reversible. Serious and fatal reactions such as anaphylactic shock after computed tomography (CT) enhancement have been described. However, there is no data on these events in the literature.Objective: This report describes a case of a serious anaphylactic reaction, possibly related to iodixanol and provides an overview of case reports.Case Summary: A 47-year-old women who experienced persistent abdominal pain for more than one month, was proposed of hiatal hernia with CT images taken two weeks previously and was admitted to the gastrointestinal surgery department. The patient underwent contrast-enhanced abdominal CT for the evaluation of multiple intraperitoneal hemodynamic features. A few minutes after abdominal enhanced CT scan, the patient was pale, sweating, had muscle tension and trembling, even coma and profound hypotension with 90/43 mm Hg. Immediately she was supported with oxygen inhalation, was treated with adrenaline subcutaneously, dexamethasone intravenously, and rapid intravenous drip of compound sodium chloride. Ten minutes later, the patient was in respiratory and cardiac arrest and the pupils were dilated. CPR and intermittant static push of 1 mg adrenaline were immediately carried. After endotracheal intubation, the patient’s spontaneous heart rate and pupils recovered, and her blood pressure recovered to 105/53 mm Hg. It was suggested that the patient was suffering from iodixanol-induced anaphylactic shock and nephropathy, and she was transferred to the intensive care unit. Despite immediate treatment, the patient died.Conclusion: A 47-year-old female patient with no history of allergies developed severe fatal anaphylactic shock after receiving iodixanol. Although contrast agents induced anaphylactoid/anaphylactic reactions do not often occur, clinicians should be conscious of the potentially serious anaphylactic reaction, which could lead to a life-threatening or fatal event.Keywords: radiocontrast media, iodixanol, anaphylaxis, shock, nephropathy

In the last decade, research has shown that most diseases are associated with organelle dysfunction in which metabolites play a crucial role or indicate specific processes. Peroxisomes are cellular organelles attracting an increasing amount of attention and are now recognized as essential players in physiological conditions and diseases. However, a limited amount of research focuses on isolating the organelles and studying their properties and the diseases resulting from organelle dysfunction. All methods for isolating peroxisomes are based on fresh tissue samples. To the best of our knowledge, this is the first work in which peroxisomes have been isolated from frozen rat liver. In our work, we isolated peroxisomes from frozen rat liver at −80 °C and evaluated the separation success and degree of purification of isolated peroxisomes by measuring the relative specific activity, purification fold, and percentage yield (Y%) of organelle marker enzymes in the isolated fractions. The percentage of protein distribution and density was also estimated. Our results showed that the purified peroxisome fraction (F3-peroxisome) had significantly higher relative specific activity, as well as the highest purification fold and percentage yield of catalase compared with the enzyme markers of other organelles in the postnuclear supernatant (PNS), postmitochondrial supernatant (PMS), and light mitochondria–peroxisome (LM-P) fractions. In addition, the percentage of protein distribution was significantly lower in the F3-peroxisome fraction compared with PNS, PMS, and LM-P fractions while the percentage of protein distribution and density of the F3-peroxisome fraction after iodixanol centrifugation were significantly higher than those of the F1 and F2 fractions. The present work demonstrates the possibility of isolating peroxisomes from frozen liver samples efficiently, which could pave the way for further research in the future on other subcellular organelles from frozen samples. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the effect of the comparative study of contrast media for gastrography of the mynah bird. This study was conducted on 12 adult male mynah birds. Using different contrast agents, all the birds were studied five times, with a minimum of two days of the time interval between each study. Radiographic tests were performed 1, 5, 15, 30, 60, and 90 minutes after ingesting the contrast agent via using a gavage tract; imaging was performed at a time interval of 30 minutes and continued until the time when the contrast agent reached the cloaca and was excreted. There was a statistically significant difference between the results of digestive system studies using Iodixanol, Iohexol, and barium sulfate in terms of mean scores of the contrast agent’s ability to fill different parts of the gastrointestinal tract, clarity of observations, and observing details of the gastrointestinal tract at all times of radiography (p < 0.05). Iodixanol is less nephrotoxic and is a better contrast agent, however, we do not recommend using Iodixanol and Iohexol diluted by water at a ratio of 1:1. [ABSTRACT FROM AUTHOR]

Iodixanol is an iso-osmolar non-ionic dimeric hydrophilic contrast agent with a higher viscosity than the monomeric agents. It is the only Food and Drug Administration (FDA)-approved iso-osmolar agent in the United States, and it is the only contrast agent with an FDA-approved indication for use in cardiac computed tomographic angiography (CCTA), to assist in the diagnostic evaluation of patients with suspected coronary artery disease. In clinical studies, it has been noted to have fewer side effects and similar image quality when compared to low-osmolar contrast media. This can be attributed to the pharmacological properties of iodixanol. These contrast agents are used for coronary computed tomography angiography and cardiac catheterization. In this article, the use, tolerability, and efficacy of iodixanol are reviewed, specifically evaluating the use of CCTA and coronary angiography, including outcome studies, randomized trials, and comparisons to other contrast agents.

We have studied a method for making microbial cells transparent by immersing them in a solution with a high refractive index (RI). When the RI of the solution was matching that of the cells, light scattering was greatly diminished (by a factor of up to about 100) and the cell suspension became transparent, facilitating the spectrophotometric determination of intracellular compounds such as hemoglobin. We investigated the properties of several compounds such as sucrose, glycerol, bovine serum albumin, FicollTM, and iodixanol (OptiprepTM), each with advantages and disadvantages. Particularly good overall properties were found for iodixanol at a concentration of around 36% (w/v) and bovine serum albumin at a concentration of about 30% (w/v). By using this RI-matching principle the production of intracellular compounds can easily be followed in near real-time during fermentation processes. For example, some conditions for producing plant hemoglobin in Escherichia coli were conveniently determined without the need of any cell disintegration or product purification.

In the last decade, research has shown that most diseases are associated with organelle dysfunction in which metabolites play a crucial role or indicate specific processes. Peroxisomes are cellular organelles attracting an increasing amount of attention and are now recognized as essential players in physiological conditions and diseases. However, a limited amount of research focuses on isolating the organelles and studying their properties and the diseases resulting from organelle dysfunction. All methods for isolating peroxisomes are based on fresh tissue samples. To the best of our knowledge, this is the first work in which peroxisomes have been isolated from frozen rat liver. In our work, we isolated peroxisomes from frozen rat liver at −80 °C and evaluated the separation success and degree of purification of isolated peroxisomes by measuring the relative specific activity, purification fold, and percentage yield (Y%) of organelle marker enzymes in the isolated fractions. The percentage of protein distribution and density was also estimated. Our results showed that the purified peroxisome fraction (F3-peroxisome) had significantly higher relative specific activity, as well as the highest purification fold and percentage yield of catalase compared with the enzyme markers of other organelles in the postnuclear supernatant (PNS), postmitochondrial supernatant (PMS), and light mitochondria–peroxisome (LM-P) fractions. In addition, the percentage of protein distribution was significantly lower in the F3-peroxisome fraction compared with PNS, PMS, and LM-P fractions while the percentage of protein distribution and density of the F3-peroxisome fraction after iodixanol centrifugation were significantly higher than those of the F1 and F2 fractions. The present work demonstrates the possibility of isolating peroxisomes from frozen liver samples efficiently, which could pave the way for further research in the future on other subcellular organelles from frozen samples.

Sustainable production and use of carbon nanotube (CNT)-enabled materials require efficient assessment of CNT environmental hazards, including the potential for CNT bioaccumulation and biomagnification in environmental receptors. Microbes, as abundant organisms responsible for nutrient cycling in soil and water, are important ecological receptors for studying the effects of CNTs. Quantification of CNT association with microbial cells requires efficient separation of CNT-associated cells from individually dispersed CNTs and CNT agglomerates. Here, we designed, optimized, and demonstrated procedures for separating bacteria (Pseudomonas aeruginosa) from unbound multiwall carbon nanotubes (MWCNTs) and MWCNT agglomerates using sucrose density gradient centrifugation. We demonstrate separation of protozoa (Tetrahymena thermophila) from MWCNTs, bacterial agglomerates, and protozoan fecal pellets by centrifugation in an iodixanol solution. The presence of MWCNTs in the density gradients after centrifugation was determined by quantification of 14C-labeled MWCNTs; the recovery of microbes from the density gradient media was confirmed by optical microscopy. Protozoan intracellular contents of MWCNTs and of bacteria were also unaffected by the designed separation process. The optimized methods contribute to improved efficiency and accuracy in quantifying MWCNT association with bacteria and MWCNT accumulation in protozoan cells, thus supporting improved assessment of CNT bioaccumulation.

Objective(s): Early diagnosis of cancer using noninvasive imaging techniques has been discussed in several recent studies. The present study aimed to assess the synergistic effects of iodixanol-conjugated polyethylene glycol (PEG)-citrate (anionic linear globular) dendrimer G2 on MCF-7 breast cancer cells and human embryonic kidney 293 (HEK293) cells. Materials and Methods: PEG-citrate dendrimer G2 was synthesized and purified. The product was characterized using atomic force microscopy (AFM), electron energy loss spectroscopy (EELS), dynamic light scattering (DLS). At the next stage, the product was conjugated to iodixanol, purified and lyophilized. The cytotoxic effects of the iodixanol, plain PEG-citrate dendrimer G2, and iodixanol-PEG-citrate dendrimer G2 complex were evaluated using methylthiazole-tetrazolium (MTT) assay on the MCF-7 and HEK293 cells. Inductively coupled plasma mass spectrometry (ICP MS) is a mass spectrometry technique, which applies inductively coupled plasma to ionize samples.Results: According to the obtained results, the uptake of PEG-citrate dendrimer G2 iodixanol increased significantly compared to iodixanol alone (PConclusion: Therefore, it was concluded that the addition of anionic linear globular dendrimer G2 to iodixanol affected the cellular uptake of the drug with no significant toxicity. Recent findings also confirmed that this novel complex could be applied as an effective cancer imaging agent for molecular biology and molecular imaging applications.

Abstract Background Contrast-induced encephalopathy (CIE) is a rare complication of cardiac catheterization; clinical manifestations include cortical blindness, seizures and focal neurological deficits. In general, recurrent epileptic seizures following cardiac catheterization with iodixanol occur more rarely than do other complications. Case presentation Here, we report a case of a 76-year-old male patient who experienced unstable angina for nearly 10 months and was admitted to our hospital. Repeat cardiac catheterization was performed using iodixanol. At approximately 20 h after the first cardiac catheterization, his upper limbs began to exhibit slight trembling; the patient was conscious and could not control these movements. A total of 6 episodes occurred before the second cardiac catheterization was performed, with each episode lasting approximately 2 s. These symptoms were not treated. At approximately 2 h after the second cardiac catheterization, the symptoms became more severe, and the frequency of the episodes increased significantly; the symptoms had fully subsided at 6 h after the second operation. An electroencephalogram (EEG) demonstrated diffuse slowing with epileptiform abnormalities. Paroxysmal spike-wave and slow wave discharges were observed in the bilateral areas, and the abnormalities were marked in the frontal areas. These observations led us to conclude that the patient was experiencing epileptic seizures. During 6 months of monthly clinical follow-up visits after discharge, no abnormalities of the nervous system were found by cardiologists or neurologists, and the patient’s EEG was normal. No antiepileptic drugs were administered throughout this process. Conclusions CIE, especially recurrent epileptic seizures, is a rare but often reversible complication of cardiac catheterization with iodixanol. Its symptoms can be mild and therefore are easily ignored by physicians. Early CIE detection may be achieved by EEG. Repeated exposure to contrast agents carries the risk of recurrent epileptic seizures.

Objective(s): Early diagnosis of cancer using noninvasive imaging techniques has been discussed in several recent studies. The present study aimed to assess the synergistic effects of iodixanol-conjugated polyethylene glycol (PEG)-citrate (anionic linear globular) dendrimer G2 on MCF-7 breast cancer cells and human embryonic kidney 293 (HEK293) cells. Materials and Methods: PEG-citrate dendrimer G2 was synthesized and purified. The product was characterized using atomic force microscopy (AFM), electron energy loss spectroscopy (EELS), dynamic light scattering (DLS). At the next stage, the product was conjugated to iodixanol, purified and lyophilized. The cytotoxic effects of the iodixanol, plain PEG-citrate dendrimer G2, and iodixanol-PEG-citrate dendrimer G2 complex were evaluated using methylthiazole-tetrazolium (MTT) assay on the MCF-7 and HEK293 cells. Inductively coupled plasma mass spectrometry (ICP MS) is a mass spectrometry technique, which applies inductively coupled plasma to ionize samples. Results: According to the obtained results, the uptake of PEG-citrate dendrimer G2 iodixanol increased significantly compared to iodixanol alone (P<0.05), indicating the importance of lack of significant in-vitro toxicity. Moreover, in the particle size and higher negative zeta potential confirmed the loading of iodixanol in dendrimer G2. Increase, the loading of iodixanol in dendrimer was confirmed by the chemical shifts in HNMR. Conclusion: Therefore, it was concluded that the addition of anionic linear globular dendrimer G2 to iodixanol affected the cellular uptake of the drug with no significant toxicity. Recent findings also confirmed that this novel complex could be applied as an effective cancer imaging agent for molecular biology and molecular imaging applications. [ABSTRACT FROM AUTHOR]

Background: Contrast-induced encephalopathy (CIE) is a rare complication of cardiac catheterization; clinical manifestations include cortical blindness, seizures and focal neurological deficits. In general, recurrent epileptic seizures following cardiac catheterization with iodixanol occur more rarely than do other complications.Case Presentation: Here, we report a case of a 76-year-old male patient who experienced unstable angina for nearly 10 months and was admitted to our hospital. Repeat cardiac catheterization was performed using iodixanol. At approximately 20 h after the first cardiac catheterization, his upper limbs began to exhibit slight trembling; the patient was conscious and could not control these movements. A total of 6 episodes occurred before the second cardiac catheterization was performed, with each episode lasting approximately 2 s. These symptoms were not treated. At approximately 2 h after the second cardiac catheterization, the symptoms became more severe, and the frequency of the episodes increased significantly; the symptoms had fully subsided at 6 h after the second operation. An electroencephalogram (EEG) demonstrated diffuse slowing with epileptiform abnormalities. Paroxysmal spike-wave and slow wave discharges were observed in the bilateral areas, and the abnormalities were marked in the frontal areas. These observations led us to conclude that the patient was experiencing epileptic seizures. During 6 months of monthly clinical follow-up visits after discharge, no abnormalities of the nervous system were found by cardiologists or neurologists, and the patient's EEG was normal. No antiepileptic drugs were administered throughout this process.Conclusions: CIE, especially recurrent epileptic seizures, is a rare but often reversible complication of cardiac catheterization with iodixanol. Its symptoms can be mild and therefore are easily ignored by physicians. Early CIE detection may be achieved by EEG. Repeated exposure to contrast agents carries the risk of recurrent epileptic seizures. [ABSTRACT FROM AUTHOR]

Contrast-induced encephalopathy (CIE) is a rare complication of the intravascular application of a contrast agent. CIE can be manifested by headache, cortical blindness, consciousness disorders, seizures, or focal neurological deficit. Neurological symptoms are typically transient with temporary abnormal findings on a brain scan. Urgent neuroimaging is important to obtain the correct diagnosis, especially in cases that require an acute management and treatment. We present a case of CIE after a digital subtraction angiography of the vertebral arteries in the patient with a symptomatic pre-occlusive stenosis of the posterior cerebral artery. [ABSTRACT FROM AUTHOR]

Background: Coronary computed tomography angiography (CCTA) is obtained using peripheral intravenous iodinated contrast agents (ICA) injection. There is continuing attempts to derive coronary physiological information like coronary blood flow (CBF) and/or fractional flow reserve from CCTA images. However, no data is available regarding the effect of peripheral intravenous injection of ICA on CBF. Methods: A series of 4 experiments was performed using healthy mongrel dogs. All dogs underwent anesthesia and open thoracotomy with placement of ultrasound flowmeter to one of the coronary artery to provide real time absolute CBF measurements. Different infusion protocols of Isovue-370 and Visipaque-320 were injected into a peripheral vein. Similar doses of normal saline injection were performed to be used as controls. The effect of iodinated contrast media injection on absolute coronary blood flow was monitored and recorded. Results: Injection of normal saline in the peripheral vein did not produce any significant increase in CBF. Peripheral intravenous injection of ICA resulted in a consistent increase of 40–73% in absolute CBF as recorded 5 minutes post-contrast administration. The contrast effect starts about 30 seconds and peaks at about 2 minutepost-contrast injection then slowly fades away in the following 10–15 min. The increase in the CBF was dose related. There was greater increase in the CBF to 50 ml infusion compared to 25 ml infusion of both Visipaque and Isovue. Conclusions: Peripheral venous administration of iodinated contrast-media in dogs results in a dose related, significant and prolonged increase in CBF.

Iodixanol is a non-ionic iso-osmolar contrast agent, but it is a risk factor for kidney damage and increases morbidity and mortality. In this study, we investigated the effect of 9 sesquiterpenes isolated from mugwort (Artemisia argyi) in contrast agent-induced cytotoxicity in LLC-PK1 cells. Cells were exposed to nine sesquiterpene compounds for 2 h, followed by incubation with iodixanol for 3 h. Cell viability was assessed using the Ez-Cytox assay. The level of reactive oxygen species was measured using 2′,7′-dichlorodihydrofluorescein diacetate staining. Apoptotic cell death was detected using annexin V/PI staining. In addition, immunofluorescence staining and western blotting were performed using antibodies against proteins related to apoptosis, oxidative stress, and MAPK pathways. The most effective 3-epi-iso-seco-tanapartholide (compound 8) among the 9 sesquiterpene compounds protected LLC-PK1 cells from iodixanol-induced cytotoxicity, oxidative stress, and apoptotic cell death. Pretreatment with compound 8 reversed iodixanol-induced increases in the expression of JNK, ERK, p38, Bax, caspase-3, and caspase-9. It also reversed the iodixanol-induced decrease in Bcl-2 expression. Furthermore, pretreatment with compound 8 caused nuclear translocation of Nrf2 and upregulated HO-1 via the Nrf2 pathway in iodixanol-treated LLC-PK1 cells. Thus, we demonstrated here that compound 8 isolated from A. argyi has the potential to effectively prevent iodixanol-induced kidney epithelial cell death via the caspase-3/MAPK pathways and HO-1 via the Nrf2 pathway.

Background: Extracellular vesicles (EVs) (isolated from blood plasma) are currently being extensively researched, both as biomarkers and for their therapeutic possibilities. One challenging aspect to this research is the efficient isolation of high-purity EVs from blood plasma in quantities sufficient for in vivo experiments. In accordance with this challenge, the aim of this study was to develop an isolation method in which to separate the majority of EVs from major impurities such as lipoprotein particles and the abundant plasma proteins albumin and fibrinogen.Methods: Samples of rat blood were centrifuged to remove cells, platelets, large EVs and protein aggregates without prior filtration. Density gradient ultracentrifugation was performed by loading plasma sample onto 50, 30, and 10% iodixanol layers and then centrifuged at 120,000 ×g for 24 h. Ten fractions (F1-10) were collected from top to bottom. Fractions with the highest EV content were further purified by ultracentrifugation, size exclusion, or bind-elute chromatography. Efficiency and purity were assessed by Western blots. Morphology and size distribution of particles were examined by dynamic light scattering and electron microscopy (EM).Results: The highest band intensities of EV markers Alix, Tsg101 and CD81 were detected by Western blot in F6 of small-scale DGUC (61.5 ± 10.4%; 48.1 ± 5.8%; 41.9 ± 3.8%, respectively) at a density of 1.128–1.174 g/mL, where the presence of vesicles with a mean diameter of 38 ± 2 nm was confirmed by EM and DLS. Only 1.4 ± 0.5% of LDL and chylomicron marker, 3.0 ± 1.3% of HDL marker, and 9.9 ± 0.4% of albumin remained in the EV-rich F6. However, 32.8 ± 1.5% of the total fibrinogen beta was found in this fraction. Second-step purification by UC or SEC did not improve EV separation, while after BEC on HiScreen Capto Core 700 albumin and lipoprotein contamination were below detection limit in EV-rich fractions. However, BEC decreased efficiency of EV isolation, and fibrinogen was still present in EV-rich fractions.Conclusion: This is the first demonstration that DGUC is able to markedly reduce the lipoprotein content of EV isolates while it separates EVs with high efficiency. Moreover, isolation of lipoprotein- and albumin-free EVs from blood plasma can be achieved by DGUC followed by BEC, however, on the expense of reduced EV yield.

MicroRNAs are small gene-regulatory RNAs that are found in various biological fluids, including milk, where they are often contained inside extracellular vesicles (EVs), like exosomes. In a previous study, we reported that commercial dairy cow’s milk microRNAs resisted simulated digestion and were not exclusively associated with canonical exosomes. Here, we report the characterization of a milk EV subset that sediments at lower ultracentrifugation speeds and that contains the bulk of microRNAs. Milk EVs were isolated by differential ultracentrifugation and Iodixanol density gradient (IDG), and analysed for (1) microRNA enrichment by reverse transcription and quantitative polymerase chain reaction (RT-qPCR), and (2) EV-associated proteins by Western blot. Milk EVs were characterized further by dynamic light scattering (DLS), density measurements, fluorescent DiR and RNA labelling, high-sensitivity flow cytometry (HS-FCM), transmission electron microscopy (TEM), proteinase K and RNase A assay, and liquid chromatography tandem-mass spectrometry (LC-MS/MS). We found that the bulk of milk microRNAs (e.g., bta-miR-125b, bta-miR-148a, etc.) sediment at 12,000 g and 35,000 g. Their distribution pattern was different from that of exosome-enriched proteins, but similar to that of several proteins commonly found in milk fat globule membranes (MFGM), including xanthine dehydrogenase (XDH). These low-speed ultracentrifugation pellets contained cytoplasm-enclosing phospholipid bilayered membrane vesicles of a density comprised between 1.11 and 1.14 g/mL in Iodixanol. This milk EV subset of ~100 nm in diameter/~200 nm hydrodynamic size resisted to proteinase K digestion and protected their microRNA content from RNase A digestion. Our results support the existence of a milk EV subset pelleting at low ultracentrifugations speeds, with a protein coating comparable with MFGM, which contains and protects the bulk of milk microRNAs from degradation. This milk EV subset may represent a new EV population of interest, whose content in microRNAs and proteins supports its potential bioactivity.

Objective- To evaluate and compare the radiographic efficacy and safety of a non-ionic dimeric and isotonic iodinated contrast medium, iodixanol (320 mgI/ml) and a non-ionic monomer and hypertonic contrast medium, iohexol (300 mgI/ml) in feline cervical myelography. Design- Experimental study Animals- Five adult healthy cats. Procedures- Iodixanol and iohexol were injected into the cerebellomedullary cistern. Radiographs were obtained immediately, 10, 20, 40 and 60 minutes after injection. The myelograms were scored and analyzed for statistical significance. Results- Diagnostically adequate radiographic examinations were obtained with both agents. Adequate opacity in thoracic and lumbar vertebrae was obtained after 10 and 20 minutes post injection for both contrast agents. After 40 minutes contrast agents were had reached the end of lumbar vertebrae column. No significant differences in scoring for image quality were observed between two contrast mediums (p>0.05). Iodixanol and iohexol radiopacified cervical region immediately after injection. Adequate opacity in thoracic and lumbar vertebrae was obtained after 10 and 20 minutes post injection for both contrast agents. Evaluation of each of the radiographs showed good to excellent opacification. No clinical and neurological abnormalities were found related to the myelographic procedure during one week after injection. Vital signs, CBC and some serum biochemical examinations remain in normal ranges. Conclusion and Clinical Relevance- Iodixanol and iohexol proved to be safe and effective contrast materials for myelographic studies in cats. More mean score of iodixanol suggests that, it is preferable to perform myelography with iodixanol.

Iodixanol is an iso-osmolar non-ionic dimeric hydrophilic contrast agent with a higher viscosity than the monomeric agents. It is the only Food and Drug Administration (FDA)-approved iso-osmolar agent in the United States, and it is the only contrast agent with an FDA-approved indication for use in cardiac computed tomographic angiography (CCTA), to assist in the diagnostic evaluation of patients with suspected coronary artery disease. In clinical studies, it has been noted to have fewer side effects and similar image quality when compared to low-osmolar contrast media. This can be attributed to the pharmacological properties of iodixanol. These contrast agents are used for coronary computed tomography angiography and cardiac catheterization. In this article, the use, tolerability, and efficacy of iodixanol are reviewed, specifically evaluating the use of CCTA and coronary angiography, including outcome studies, randomized trials, and comparisons to other contrast agents.

Background: Extracellular vesicles (EVs) (isolated from blood plasma) are currently being extensively researched, both as biomarkers and for their therapeutic possibilities. One challenging aspect to this research is the efficient isolation of high-purity EVs from blood plasma in quantities sufficient for in vivo experiments. In accordance with this challenge, the aim of this study was to develop an isolation method in which to separate the majority of EVs from major impurities such as lipoprotein particles and the abundant plasma proteins albumin and fibrinogen. Methods: Samples of rat blood were centrifuged to remove cells, platelets, large EVs and protein aggregates without prior filtration. Density gradient ultracentrifugation was performed by loading plasma sample onto 50, 30, and 10% iodixanol layers and then centrifuged at 120,000 × g for 24 h. Ten fractions (F1-10) were collected from top to bottom. Fractions with the highest EV content were further purified by ultracentrifugation, size exclusion, or bind-elute chromatography. Efficiency and purity were assessed by Western blots. Morphology and size distribution of particles were examined by dynamic light scattering and electron microscopy (EM). Results: The highest band intensities of EV markers Alix, Tsg101 and CD81 were detected by Western blot in F6 of small-scale DGUC (61.5 ± 10.4%; 48.1 ± 5.8%; 41.9 ± 3.8%, respectively) at a density of 1.128–1.174 g/mL, where the presence of vesicles with a mean diameter of 38 ± 2 nm was confirmed by EM and DLS. Only 1.4 ± 0.5% of LDL and chylomicron marker, 3.0 ± 1.3% of HDL marker, and 9.9 ± 0.4% of albumin remained in the EV-rich F6. However, 32.8 ± 1.5% of the total fibrinogen beta was found in this fraction. Second-step purification by UC or SEC did not improve EV separation, while after BEC on HiScreen Capto Core 700 albumin and lipoprotein contamination were below detection limit in EV-rich fractions. However, BEC decreased efficiency of EV isolation, and fibrinogen was still present in EV-rich fractions. Conclusion: This is the first demonstration that DGUC is able to markedly reduce the lipoprotein content of EV isolates while it separates EVs with high efficiency. Moreover, isolation of lipoprotein- and albumin-free EVs from blood plasma can be achieved by DGUC followed by BEC, however, on the expense of reduced EV yield. [ABSTRACT FROM AUTHOR]

Effects of radiographic contrast media (RCM) application were demonstrated in vitro and in vivo where the injection of RCM into the A. axillaris of patients with coronary artery disease was followed by a significant and RCM-dependent decrease of erythrocyte velocity in downstream skin capillaries. Another study in pigs revealed that the deceleration of erythrocytes coincided with a significant reduction of the oxygen partial pressure in the myocardium—supplied by the left coronary artery—after the administration of RCM into this artery. Further reports showed RCM dependent alterations of erythrocytes like echinocyte formation and exocytosis, sequestration of actin or band 3 and the buckling of endothelial cells coinciding with a formation of interendothelial fenestrations leading to areas devoid of endothelial cells. Key to morphological alterations of erythrocytes is the membrane cytoskeleton, which is linked to the band 3 in the erythrocyte membrane via the junctional complex. Fundamental observations regarding the cell biological and biochemical aspects of the structure and function of the cell membrane and the membrane cytoskeleton of erythrocytes have been reported. This review focuses on recent results gained, e.g., by advanced confocal laser scanning microscopy of different double-stained structural elements of the erythrocyte membrane cytoskeleton.

We investigated whether 14 phenolic compounds isolated from Artemisia argyi could prevent the apoptotic damage caused by iodixanol, an iodinated contrast agent, on LLC-PK1 cells. Iodixanol was used to induce cytotoxicity in LLC-PK1 cells. Apoptotic cell death was observed as the fluorescence intensity emitted by annexin V and Hoechst 33342 stains. Western blotting was used to detect specific proteins. Seven phenolic compounds protected against iodixanol-induced LLC-PK1 cell death in a concentration-dependent manner. Among them, methyl caffeate exerted the strongest protective effect, and co-treatment with 50 and 100 μM methyl caffeate decreased intracellular reactive oxygen species elevated by 25 mg/mL iodixanol. In addition, the treatment of LLC-PK1 cells with iodixanol resulted in an increase in apoptotic cell death, which decreased by co-treatment with methyl caffeate. Iodixanol caused a cytotoxicity-related increase in the phosphorylation of extracellular-signal-regulated kinase, c-Jun N-terminal kinase, and P38; and a similar increase in the expression levels of kidney injury molecule-1 and cleaved caspase-3. However, the up-regulation of these proteins was reversed by co-treatment with methyl caffeate. These findings suggest that phenolic compounds isolated from A. argyi play an important role in protecting kidney epithelium cells against apoptotic damage caused by iodixanol.

This study investigates the effects of iodixanol supplementation in varied concentrations to Tris egg yolk ( TEY) extender on the quality and fertilization ability of frozen-thawed sperm of Thai native bulls. Each ejaculate was divided into four different groups, as follows: sperm were treated with TEY extender (control group) and TEY extender supplemented with three different concentrations of iodixanol (1.25%, 2.50% and 5.00%). Semen straws were frozen in liquid nitrogen vapor. After thawing, sperm motility characteristics, viability, plasma membrane integrity and acrosome integrity were determined. Also, frozen-thawed spermatozoa from all groups were used for in vitro fertilization and artificial insemination ( AI) in natural estrus Thai native cows. The results showed that the post-thaw quality of the 2.50% iodixanol group was superior to the other iodixanol groups ( P < 0.05). However, iodixanol had no beneficial effect on post-thaw sperm in vitro fertilization ability and pregnancy rate after AI ( P > 0.05). It can be concluded that the supplementation of 2.50% iodixanol extender significantly improves the progressive motility, viability, plasma membrane integrity and acrosome integrity of cryopreserved semen from Thai native bulls, but it has no beneficial effect on in vitro fertilization ability and pregnancy rate after AI. [ABSTRACT FROM AUTHOR]

The application of biomaterials used in regenerative endodontics should be traceable. In this study, we checked some basic effects of rendering a fibrin hydrogel radiopaque using an iodine-based contrast agent (iodixanol) approved for systemic application. Fibrin hydrogels were prepared from a fibrin sealant (Tisseel) using either an isotonic iodixanol solution (Visipaque 320, test) or Tris buffer (control) as a diluent. Gelation kinetics, radiopacity, and swelling of lyophilized hydrogels were tested using standard methods. Hydrogel structure was evaluated using scanning electron microscopy (SEM). Furthermore, iodixanol release fromthe test gels was assessed using spectrophotometry, and tissue compatibility was compared between test and control hydrogels using the chick chorioallantoic membrane (CAM) assay. Results were compared using pairwise t-test, p < 0.05. Iodixanol caused a 70-fold delay in gelation to 26min in the test compared to the control hydrogels (22 ± 1 s). Radiopacity of the test gels was 1.9 ± 0.2 mm Al/mm, compared to zero in the control hydrogels. Lyophilized hydrogel swelling was strongly reduced when iodixanol was added to the hydrogel (p < 0.05). Test hydrogels had an altered SEM appearance compared to controls, and exhibited a reduced porosity. Iodixanol release from the test hydrogels reached 14.5 ± 0.5% after 120 h and then ceased. This release did not have any apparent toxic effect and neither affected the viability, nor the physiology or vascularization of the CAM of fertilized chicken eggs. Iodixanol can render a fibrin hydrogel radiopaque and maintains its tissue compatibility, yet impacts gelation kinetics and hydrogel porosity. [ABSTRACT FROM AUTHOR]

Objectives: The iso-osmolar contrast agent iodixanol may be associated with fewer contrast-induced acute kidney injuries when compared with low-osmolar contrast agents. The aim of this study is to compare iodixanol and iopamidol in patients with acute coronary syndrome (ACS) who are currently undergoing coronary angiography. Study design: Two hundred and seventy five consecutive patients who presented to a tertiary cardiovascular center with acute non-ST elevation myocardial infarction and underwent coronary angiography as a part of an early invasive strategy were included in the study (mean age 58+-11 years, 79% male). Study participants were administered either iodixanol (n=45) or iopamidol (n=230) and the groups were compared for the highest creatinine levels, the absolute and percent change in creatinine levels, and for the development of contrast induced nephropathy within 72 hours of the procedure. Results: Baseline demographic and clinical characteristics of the patients were similar between the two groups. There were no differences in the preprocedural serum creatinine (iopamidol 1.10+-0.54 mg/dl, iodixanol 1.09+-0.24 mg/dl, p=0.680), glomerular filtration rate (iopamidol 89+-35 ml/dk/1.73 m2, iodixanol 89+-26 ml/dk/1.73 m2, p=0.934), or contrast volume used during the procedure (iopamidol 180+-80 ml vs. iodixanol 166+-73 ml, p=0.226) between the groups. The absolute change in serum creatinine after the procedure (iopamidol 0.136+-0.346 mg/dl, iodixanol 0.072+-0.070 mg/dl, p=0.118) and the percent change in serum creatinine after the procedure (iopamidol 12.1+-29.6%, iodixanol 6.8+-6.9%, p=0.075) were not statistically significant between the two groups. Contrast induced nephropathy developed 10% (95% confidence interval [CI] 6–14%) in iopamidol group whereas it was 2.2% (95% CI -2-7%) in iodixanol group (p=0.144). Conclusion: Iodixanol was not superior to iopamidol regarding contrast induced acute kidney injury after coronary angiography in an unselected general patient population with ACS.

There are many indications for excretory urography in humans and animals. Intravenous urography (IVU) is the most practical method about other urography techniques are used because of difficulties for finding veins in IVU, due to small size of the patients. This study was performed to evaluate the feasibility of subcutaneous injection of iodixanol in providing a safe and diagnostic urogram in Persian squirrel. Twelve clinically healthy adult Persian squirrels were prepared and kept for two weeks prior to study. Blood tests were performed 7 days prior to the study. After eighteen hour fasting, animals were sedated by using xylazine/diazepam cocktail (xylazine 5mg/kg, diazepam 30mg/kg). Lateral and ventrodorsal control radiographs were taken. Thirteen hundred and 1800 mg iodine per kilogram body weight of iodixanol was injected subcutaneously over shoulder area in Persian squirrels (each dose for six Persian squirrels). Lateral and ventrodorsal radiographs were taken every 5 minutes until the pyelogram was finished. Blood tests were performed 5 days after the study. Histopathologic samples were taken from skin, kidneys, ureters and urinary bladder. The kidneys of squirrels were bean-shaped and their size was approximately 1.7×0.8 cm in ventrodorsal view for both kidneys. Subcutaneous injection of iodixanol was successful to show pyelogram, uretrogram and cystogram but it was unsuccessful in showing nephrogram without pyelogram except in one case (8.33%). Good pictures of nephrograms, calices and the ureters were obtained approximately 70 min after injection. There were no abnormal clinical signs after one week of experiment. There were no abnormal blood chemistry and hematological changes. Urinary system and skin microscopic examinations were normal. It is concluded that subcutaneous urography is an effective and reliable method for urography studies in squirrel except for nephrogram. More investigations are needed to study reasons for the lack of nephrogram, it may be due to incomplete preparation.

Preventive effects and corresponding molecular mechanisms of mugwort (Artemisia argyi) extract and its flavonoid constituents on contrast-induced nephrotoxicity were explored in the present study. We treated cultured LLC-PK1 cells with iodixanol to induce contrast-induced nephrotoxicity, and found that A. argyi extracts ameliorated the reduction in cellular viability following iodixanol treatment. The anti-apoptotic effect of A. argyi extracts on contrast-induced nephrotoxicity was mediated by the inhibition of mitogen-activated protein kinase (MAPK) phosphorylation and the activation of caspases. The flavonoid compounds isolated from A. argyi improved the viability of iodixanol-treated cells against contrast-induced nephrotoxicity. Seven compounds (1, 2, 3, 15, 16, 18, and 19) from 19 flavonoids exerted a significant protective effect. Based on the in silico oral-bioavailability and drug-likeness assessment, which evaluate the drug potential of these compounds, compound 2 (artemetin) showed the highest oral bioavailability (49.55%) and drug-likeness (0.48) values. We further investigated the compound–target–disease network of compound 2, and proliferator-activated receptor gamma (PPAR-γ) emerged as a predicted key marker for the treatment of contrast-induced nephrotoxicity. Consequently, compound 2 was the preferred candidate, and its protective effect was mediated by inhibiting the contrast-induced inflammatory response through activation of PPAR-γ and inhibition of MAPK phosphorylation and activation of caspases.

Renal ischemia and direct toxic effect of contrast media are the main confounding causes of contrast-induced nephropathy (CIN). The effect of different contrast mediums on the resistance of renal artery is quite unclear. The aim of the present study was to assess the resistive index (RI) changes of renal segmental artery in color Doppler duplex sonography after injection of two different contrast mediums: iodixanol and iohexol. The RI of the renal segmental artery of 62 randomly chosen patients, with a normal baseline renal function, was calculated using color-coded Doppler sonography before and five minutes after bolus injection of two different contrast mediums. Thirty-one patients were administered 50 mL of iodixanol (Visipaque) and 31 patients were admi-nistered 50 mL of iohexol (Omnipaque) during intravenous urogram procedures. The RI results were analyzed and compared in two groups using two-tailed t-test. The mean RI of renal segmental artery increased significantly after administration of contrast media (mean ± SD 0.61 ± 0.046 vs 0.58 ± 0.042; p< 0.001). The mean change of RI was 0.0387 ± .00552 (mean ± SE) in the setting of iohexol injection and 0.0216 ± .00423 (mean ± SE) five minutes after administration of iodixanol (p= 0.017). Both non-ionic iso-osmolar dimeric iodixanol and low-osmolar iohexol increase the renal artery resistance, but the changes are more dramatic with iohexol, suggesting better tolerance with iodixanol.

Sustainable production and use of carbon nanotube (CNT)-enabled materials require efficient assessment of CNT environmental hazards, including the potential for CNT bioaccumulation and biomagnification in environmental receptors. Microbes, as abundant organisms responsible for nutrient cycling in soil and water, are important ecological receptors for studying the effects of CNTs. Quantification of CNT association with microbial cells requires efficient separation of CNT-associated cells from individually dispersed CNTs and CNT agglomerates. Here, we designed, optimized, and demonstrated procedures for separating bacteria (Pseudomonas aeruginosa) from unbound multiwall carbon nanotubes (MWCNTs) and MWCNT agglomerates using sucrose density gradient centrifugation. We demonstrate separation of protozoa (Tetrahymena thermophila) from MWCNTs, bacterial agglomerates, and protozoan fecal pellets by centrifugation in an iodixanol solution. The presence of MWCNTs in the density gradients after centrifugation was determined by quantification of 14C-labeled MWCNTs; the recovery of microbes from the density gradient media was confirmed by optical microscopy. Protozoan intracellular contents of MWCNTs and of bacteria were also unaffected by the designed separation process. The optimized methods contribute to improved efficiency and accuracy in quantifying MWCNT association with bacteria and MWCNT accumulation in protozoan cells, thus supporting improved assessment of CNT bioaccumulation. [ABSTRACT FROM AUTHOR]

Background: Density gradient centrifugation was reported as a technique of semen preparation in assisted reproductive techniques in humans and animals. This technique was found to be efficient in improving semen quality after harmful techniques such as cryopreservation. Recently a modified technique, single layer centrifugation, was proposed as a technique providing a large amount of high quality spermatozoa, and this treatment was performed before conservation. Single layer centrifugation has been studied prevalently in stallions and in boars, but limited data were available for bulls. Occasionally bulls are known to experience a transient reduction in semen quality, thus techniques that allow improvement in semen quality could be applied in this context. The aim of this study was the evaluation of single layer and double layer centrifugation by the use of iodixanol, compared with conventional centrifugation and non-centrifuged semen, on the sperm characteristics during the cryopreservation process in bulls with normal and poor semen quality. Results: Single layer centrifugation and double layer centrifugation both significantly increased the percentage of normal spermatozoa and decreased the percentage of non-sperm cells in poor quality samples, while both were ineffective in those of normal quality. Sperm characteristics in poor quality samples increased after single layer centrifugation and double layer centrifugation, reaching values similar to those recorded in normal samples, and this trend is maintained after equilibration and after cryopreservation. On the other hand, SLC and DLC resulted in a consistent reduction in the spermatozoa recovered, and this resulted in a reduction of the absolute amount of spermatozoa cryopreserved in the normal samples, without a clear improvement in sperm characteristics in this type of sample. Conclusions: These data suggested that both SLC and DLC could be performed in practice, but their application should be limited to the cases in which the quality of the spermatozoa recovered is more important than the total amount of spermatozoa. [ABSTRACT FROM AUTHOR]

Background: Successful cryopreservation of rat spermatozoa from various strains still remains a challenge. The objective of this study was to determine if combinations of OptiPrepTM (iodixanol) and adenosine 5'-triphosphate (ATP) can improve rat sperm function during the cryopreservation procedure. Methods: Epididymal rat spermatozoa were frozen under different OptiPrepTM concentrations (0, 1, 2, 3 or 4 %) and were diluted with media supplemented with or without 2 mM ATP after thawing. Post-thaw sperm motility, acrosomal membrane integrity (AMI) and mitochondrial membrane potential (MMP) were then evaluated. In addition, the effect of different OptiPrepTM concentrations on fresh and cooled rat spermatozoa was tested via motility. Results: There was no effect of OptiPrepTM on motility of fresh and cooled spermatozoa. The supplementation of 1 and 2 % OptiPrepTM increased motility of frozen spermatozoa at 10 min after thawing, while it did not improve motility of spermatozoa at 3 h after thawing in the absence of ATP. During incubation of thawed spermatozoa, the ATP addition protected time-dependent decrease in motility after thawing in OptiPrepTM-treated samples. OptiPrepTM had no effect on AMI and MMP in frozen-thawed spermatozoa but combinations of OptiPrepTM and ATP improved MMP in frozen-thawed spermatozoa. Conclusions: Iodixanol has cryoprotective effects during rat sperm freezing without any toxic effect. Moreover, the combinations of iodixanol and ATP have a beneficial role in maintaining function of frozen-thawed rat spermatozoa for long period of incubation post-thaw. [ABSTRACT FROM AUTHOR]