Radiographic Contrast Media Research Articles

Development and Evaluation of Ultrasound-Guided Navicular Bursa Injection Using the Palmarodistal Digital Approach in Horses: an Ex Vivo Study

Navicular bursa injections are routinely used in horses with foot pain for diagnostic and therapeutic purposes. Ultrasound-guided injections to the navicular bursa have been proposed as an alternative to traditional techniques. The objective of this study was to develop an ultrasound-guided injection technique to access the navicular bursa using the palmarodistal digital approach and evaluate the success rate, total execution time, number of needle positioning, and ultrasonographic verification of bursal injection compared with contrast radiology. We hypothesized that this technique would be fast and accurate; necessitating few needle repositions and allowing real-time ultrasonographic guidance and verification of bursal injection. Overall success rate was 92.5% (37 of 40). Optimal images presented a success rate of 100% (32 of 32) and suboptimal images of 62.5% (5 of 8). Intrabursal accumulation of radiographic contrast media was correlated in 97.3% (36 of 37) of the limbs to ultrasonographic evidence of fluid and gas in the navicular bursa. Mean total execution time was 16.1 second (±7.84 seconds). Mean number of needle insertions per limb was 1.23 (±0.42). All the needle repositions (9 of 40) were performed within the digital cushion. Our results using cadaver limbs suggest that this approach allows a high injection success rate, high execution speed, accurate confirmation of intrabursal injection, and a low needle reposition rates. Needle repositioning within the digital cushion could minimize the number of unnecessary needle penetrations to the deep digital flexor tendon. Acquisition of suboptimal ultrasound images may preclude the use of this technique because it importantly impacts the injection success rate.

Outcome Differences between Intra-Arterial Iso- and Low-Osmolality Iodinated Radiographic Contrast Media in the Interventional Management of Stroke III Trial.

Intracarotid arterial infusion of nonionic, low-osmolal iohexol contrast medium has been associated with increased intracranial hemorrhage in a rat middle cerebral artery occlusion model compared with saline infusion. Iso-osmolal iodixanol (290 mOsm/kg H2O) infusion demonstrated smaller infarcts and less intracranial hemorrhage compared with low-osmolal iopamidol and saline. No studies comparing iodinated radiographic contrast media in human stroke have been performed, to our knowledge. We hypothesized that low-osmolal contrast media may be associated with worse outcomes compared with iodixanol in the Interventional Management of Stroke III Trial (IMS III). We reviewed prospective iodinated radiographic contrast media data for 133 M1 occlusions treated with endovascular therapy. We compared 5 prespecified efficacy and safety end points (mRS 0-2 outcome, modified TICI 2b-3 reperfusion, asymptomatic and symptomatic intracranial hemorrhage, and mortality) between those receiving iodixanol (n = 31) or low-osmolal contrast media (n = 102). Variables imbalanced between iodinated radiographic contrast media types or associated with outcome were considered potential covariates for the adjusted models. In addition to the iodinated radiographic contrast media type, final covariates were those selected by using the stepwise method in a logistic regression model. Adjusted relative risks were then estimated by using a log-link regression model. Of baseline or endovascular therapy variables potentially linked to outcome, prior antiplatelet agent use was more common and microcatheter iodinated radiographic contrast media injections were fewer with iodixanol. Relative risk point estimates are in favor of iodixanol for the 5 prespecified end points with M1 occlusion. The percentage of risk differences are numerically greater for microcatheter injections with iodixanol. While data favoring the use of iso-osmolal iodixanol for reperfusion of M1 occlusion following IV rtPA are inconclusive, potential pathophysiologic mechanisms suggesting clinical benefit warrant further investigation.

Radionuclide tagged blood cell patch to monitor spine coverage for spontaneous diffuse CSF leaks

We present a 14-year-old female patient with a 2 yr history of positional headache secondary to spontaneous diffuse cerebrospinal fluid (CSF) leaks. We treated the leak with an epidural blood patch which was radioactively labeled by a well- established nuclear medicine technique. Because spontaneous CSF leaks were frequently multifocal or diffuse throughout the spine, the extent of coverage or distribution of an epidural patch was generally determined by best estimate. Traditional radiographic contrast media mixed with the blood cellshad been used to monitor the patch coverage and it is questionable whether the contrast can be representative of the cell distribution. We applied a nuclear medicine technique to label the autologous red blood cells to monitor the range of spinal cord coverage of each epidural patch. After two visible epidural patches covered both the lumbar and thoracic spine, computed tomography myelogram demonstrated significantly decreased leakage when compared to the pre-patch images. However, the patient's symptoms remained essentially unchanged in the long term, which is consistent with refractory spontaneous CSF leaks. We believe that this sophisticated nuclear medicine blood labeling technique is a simple and accurate way to monitor the true cell coverage of the spine and the pattern of distribution.

Palpation Versus Ultrasound-Guided Acromioclavicular Joint Intra-articular Corticosteroid Injections: A Retrospective Comparative Clinical Study

Background: Primary osteoarthritis (OA) is the most common cause of pain arising from the acromioclavicular (AC) joint. The true incidence is unknown because of differences in the criteria used to define arthritis in various studies. The proper diagnosis of AC joint OA requires a thorough physical examination, radiographic findings, and a diagnostic local anesthetic injection. Objective: The goal of this study was to assess the effects and safety of ultrasound (US) versus palpation-guided acromioclavicular (AC) joint intra-articular (IA) corticosteroid injection for patients with osteoarthritis (OA) of the AC joint. Study Design: Retrospective, compared clinical study. Setting: University hospital outpatient pain clinic. Method: We retrospectively reviewed the charts of patients with AC joint degenerative OA who had undergone US or palpation-guided AC joint IA corticosteroid injection between January 2012 and December 2013 at our outpatient clinic. One hundred consecutive patients identified from chart review met inclusion criteria. Patients (N = 50) in US guide AC joint IA steroid injection group were administered a mixture of 0.5% lidocaine (1 mL) with triamcinolone (20 mg/mL; 0.5 mL) and radiographic contrast material (0.5 mL) and patients (N = 50) in palpation-guided AC joint IA steroid injection group were administered a mixture of 0.5% lidocaine (1 mL) with triamcinolone (20 mg/mL; 0.5 mL) and 0.5 mL of radiographic contrast material. Results were measured using the Shoulder Pain and Disability Index (SPADI), Verbal Numeric pain Scale (VNS) at rest (VNSar), under local pressure (VNSlp) ,and the arm adduction test (VNSaat) at the joint space area before injections and at one, 3, and 6 months after the injections. Successful treatment occurred when patients obtained significant pain relief (as measured by > 50% improvement in the VNS score and 20 point improvement in the SPADI) at one, 3, and 6 months after the injections. Univariable analysis was performed to evaluate the relationship between possible outcome predictors and therapeutic effect by using a chi-square test. Logistic regression analysis was performed to assess whether injection method, injection accuracy, patients’ age, gender, and duration of the disease were independent predictors of successful outcome. Results: SPADI, VNSaat, VNSlp, and VNSar improved at one, 3, and 6 months after the injections in both groups. There was a statistically significantly greater improvement in the VNSlp score and SPDAI at 6 months and in the VNSaat score at 3 months and 6 months for US-guided group as compared with the palpation group. Successful treatment is defined as significant differences found between the groups or from the 3-month to 6-month outcomes. Multiple logistic regression and univariable analysis showed that the significant outcome predictors at 6-month follow-up was the injection accuracy. Limitations: Limitations include the retrospective nature of the study, lack of evaluation of longterm effects , most of the injections were performed in patients with a BMI of less than 30 kg/m2, and the treatment procedures were conducted by the same physician. Conclusion: US-guided AC joint IA injection for the treatment of symptomatic AC joint OA resulted in better pain and functional status improvement than palpation-guided IA injection at the 6-month follow-up. Key Words: Ultrasound, injection, acromioclavicular joint, steroid

A method for estimating the glomerular filtration rate in conscious monkeys.

To establish a method for estimating the glomerular filtration rate (GFR) in conscious monkeys, the radiographic contrast medium iodixanol and the standard agent inulin were coadministered as tracers to male cynomolgus monkeys (Macaca fascicularis) as a bolus injection; blood was collected after 60, 90 and 120 min. An equation based on a single-blood-sample method derived from Jacobsson's formula was prepared using the data from healthy and saline- and gentamicin-treated monkeys by a multisample strategy with iodixanol. The GFR using the equation with iodixanol was in agreement with that from the multisample method with inulin or iodixanol. When the GFR decreased to more than 60% of the basal reference level, serum creatinine concentrations tended to increase, whereas serum blood urea nitrogen concentrations fluctuated. The results suggest that the single-sample-blood method with iodixanol is a practical tool for estimating the monkey GFR in a toxicological research setting therefore minimizing animal sufferings.

Nephrotoxicity of iodixanol versus iohexol inpatients with chronic kidney disease and diabetes mellitus undergoing coronary angiographic procedures

Background: The choice of radiographic contrast media for use in patients at increased risk of contrast-induced nephropathy is of ongoing interest. Materials and Methods: The current study is a prospective, randomized in which comparison of nonionic, isoosmolal agent, iodixanol, versus the nonionic, low-osmolal agent, iohexol, on the renal effects was carried out. A total of 526 subjects with impaired baseline renal functionand diabetes mellitus underwent diagnostic and/or therapeutic coronary angiographic procedures. The coprimary end points were the peak increase in serum creatinine and the incidence of contrast-induced nephropathy, that is, ≥0.5 mg/dl in serum creatinine from baseline within 72 h of receiving contrast media. Results: Of the 129 patients, 97 received iodixanol and 97 received iohexol randomly. The median peak increase in serum creatinine in the iodixanol arm was 0.10 mg/dl; whereas in the Iohexol arm, the median peak increase was 0.09 mg/dl (P = 0.13). The overall contrast-induced nephropathy incidence was 10.5% in the iodixanol arm and 9.8% in the iohexol arm (P = 0.7). The volume of contrast media, volume of saline administered, frequency of coronary interventional procedures, and severity of baseline kidney disease and of diabetes mellitus were similar between treatments. Conclusions: In the present study, the overall rate of contrast-induced nephropathy in patients with chronic kidney disease and diabetes mellitus undergoing coronary angiographic procedures was 10.5%. There was no significant difference between iodixanol and iohexol in either peak increase in serum creatinine or risk of contrast-induced nephropathy.

Nanotoxic profiling of novel iron oxide nanoparticles functionalized with perchloric acid and SiPEG as a radiographic contrast medium.

Emerging syntheses and findings of new metallic nanoparticles (MNPs) have become an important aspect in various fields including diagnostic imaging. To date, iodine has been utilized as a radiographic contrast medium. However, the raise concern of iodine threats on iodine-intolerance patient has led to search of new contrast media with lower toxic level. In this animal modeling study, 14 nm iron oxide nanoparticles (IONPs) with silane-polyethylene glycol (SiPEG) and perchloric acid have been assessed for toxicity level as compared to conventional iodine. The nanotoxicity of IONPs was evaluated in liver biochemistry, reactive oxygen species production (ROS), lipid peroxidation mechanism, and ultrastructural evaluation using transmission electron microscope (TEM). The hematological analysis and liver function test (LFT) revealed that most of the liver enzymes were significantly higher in iodine-administered group as compared to those in normal and IONPs groups (P < 0.05). ROS production assay and lipid peroxidation indicator, malondialdehyde (MDA), also showed significant reductions in comparison with iodine group (P < 0.05). TEM evaluation yielded the aberration of nucleus structure of iodine-administered group as compared to those in control and IONPs groups. This study has demonstrated the less toxic properties of IONPs and it may postulate that IONPs are safe to be applied as radiographic contrast medium.

Plasma ProBNP Is Not a Specific Marker for Transient Myocardial Ischemia.

BackgroundPlasma proBNP levels are increased in patients with acute myocardial infarction. Previous studies have shown conflicting data on the effect of transient myocardial ischemia on plasma BNP levels. We designed the current study to examine plasma proBNP levels in patients with transient myocardial ischemia during a percutaneous coronary intervention (PCI). This study was to study plasma proBNP as a marker of transient myocardial ischemia.MethodsWe enrolled 49 consecutive patients with a history of angina or abnormal stress test who presented for cardiac catheterization. We obtained plasma proBNP levels in all patients at 1) arterial access (proBNP-1), 2) the end of the procedure (proBNP-2) and 3) 4 hours after procedure (proBNP-3). Hotelling’s T-squared test was used to evaluate the equality of means. Log transforms of proBNP were used to impart data normality.ResultsTwenty-two patients underwent diagnostic catheterization (DCA group) and 27 underwent PCI (PCI group). Both groups had normal left ventricular function and a baseline creatinine < 2 mg/dL. Baseline log (proBNP) was 4.7 + 0.99 (units) and rose significantly at 4 hours in both groups (P < 0.02), with no difference in rate of change.ConclusionsPlasma proBNP was increased in both DCA and PCI groups which limits its utility to identify transient myocardial ischemia. The etiology of increase in proBNP in both groups is speculative and may be related to injection of radiographic contrast media into the coronary artery which leads to microcirculatory impairment resulting in myocardial tissue hypoxia and transient increase in left ventricular pressure; however, further evaluation is required.

Effect of N-acetylcysteine on mitochondria isolated from the rat kidney exposed to an iodinated radiographic contrast agent

Background: Contrast-induced nephropathy (CIN) is an acute complication associated with iodinated radiographic contrast agents. N-acetylcysteine (NAC), an antioxidant agent, has often been used to prevent CIN; however, reports of its efficacy are conflicting. In the kidney, mitochondrial dysfunction has been associated with acute and chronic ischemic and nephrotoxic injury. The aim of the present study was to investigate the effect of NAC on oxygen consumption in mitochondria isolated from rat kidneys exposed to a radiographic contrast agent. Methods: Four groups of Wistar rats were evaluated including a control group. The experimental groups were injected intraperitoneally with: 5 mL/kg of body weight of iobitridol (300 mg/mL); NAC (100 mL/kg at 24, 12 and 2 hours prior to saline infusion); and NAC prior to an infusion of 300 mg/mL of iobitridol. Twenty minutes after the intraperitoneal infusion of the contrast agent or saline, all the animals were sacrificed and their kidneys were collected. Oxygen consumption was measured polarographically in the sediment containing principally mitochondria. Results: Mean oxygen consumption was 14.8% higher in the group exposed to iobitridol compared to the control group. Pretreatment with NAC before the iobitridol infusion inhibited the increase in mean oxygen consumption (p&lt;0.05). There were no significant differences in the endogenous respiration of mitochondria isolated from kidneys in the control group compared to the groups treated with NAC (p&gt;0.05). Conclusion: The findings of the present study confirm a certain protective effect of NAC in rat kidneys exposed to an iodinated radiographic contrast medium.

The Choice of the Iodinated Radiographic Contrast Media to Prevent Contrast-Induced Nephropathy

In patients with preexisting renal impairment, particularly those who are diabetic, the iodinated radiographic contrast media may cause contrast-induced nephropathy (CIN) or contrast-induced acute kidney injury (CI-AKI), that is, an acute renal failure (ARF), usually nonoliguric and asymptomatic, occurring 24 to 72 hours after their intravascular injection in the absence of an alternative aetiology. Radiographic contrast media have different osmolalities and viscosities. They have also a different nephrotoxicity. In order to prevent CIN, the least nephrotoxic contrast media should be chosen, at the lowest dosage possible. Other prevention measures should include discontinuation of potentially nephrotoxic drugs, adequate hydration with i.v. infusion of either normal saline or bicarbonate solution, and eventually use of antioxidants, such as N-acetylcysteine, and statins.

Thermographic visualization of the superficial vein and extravasation using the temperature gradient produced by the injected materials

There are few effective methods to detect or prevent the extravasation of injected materials such as chemotherapeutic agents and radiographic contrast materials. To investigate whether a thermographic camera could visualize the superficial vein and extravasation using the temperature gradient produced by the injected materials, an infrared thermographic camera with a high resolution of 0.04°C was used. At the room temperature of 26°C, thermal images and the time course of the temperature changes of a paraffin phantom embedded with rubber tubes (diameter 3.2mm, wall thickness 0.8mm) were evaluated after the tubes were filled with water at 15°C or 25°C. The rubber tubes were embedded at depths of 0mm, 1.5mm, and 3.0mm from the surface of the phantom. Temperature changes were visualized in the areas of the phantom where the tubes were embedded. In general, changes were more clearly detected when greater temperature differences between the phantom and the water and shallower tube locations were employed. The temperature changes of the surface of a volunteer’s arm were also examined after a bolus injection of physiological saline into the dorsal hand vein or the subcutaneous space. The injection of 5ml room-temperature (26°C) saline into the dorsal hand vein enabled the visualization of the vein. When 3ml of room-temperature saline was injected through the vein into the subcutaneous space, extravasation was detected without any visualization of the vein. The subtraction image before and after the injection clearly showed the temperature changes induced by the saline. Thermography may thus be useful as a monitoring system to detect extravasation of the injected materials.

Hemodialysis clearance of iosimenol, a novel iso-osmolar radiographic contrast medium

Iodinated contrast media (CM) have molecular and pharmacokinetic properties likely to make them highly dialyzable. Controlled clinical studies allowing for comparisons of hemodialysis clearance between different test substances and in multiple hemodialysis filters are, however, complex and not always practically feasible. A miniaturized in vitro method was therefore developed to evaluate the dialyzability of a new CM. To evaluate hemodialysis clearance of iosimenol, a novel iso-osmolar contrast medium (CM), in a select variety of hemodialysis filters and in comparison to commercially available CM. Three different high-flux and one low-flux membrane were used in miniaturized dialyzers to evaluate the in vitro blood clearance of iosimenol. Commercially available CM (iodixanol and iohexol) served as control substances. In vitro dialysis parameters were then used to predict clinical hemodialysis clearances. Residual ratios of endogenous substances (inorganic phosphate, urea nitrogen, creatinine, total bilirubin, and albumin) were used as proof of reliability of the in vitro dialysis system. Dialyzable small endogenous molecules were readily eliminated in all membranes. The removal ratios of iosimenol were generally similar to that of iodixanol in all membranes except the high-flux polysulfone but were consistently lower than that of iohexol. The blood clearance of iosimenol during clinical hemodialysis was predicted as, on average, approximately 85 mL/min with the high-flux membranes and 47 mL/min with the low-flux membrane. The dialyzability of iosimenol was evaluated using a newly developed in vitro dialysis system, and iosimenol was readily cleared from blood with all four tested membranes. And it is suggested that the dialysis parameters can predict clinical hemodialysis clearance of CM.

Do intravenous N-acetylcysteine and sodium bicarbonate prevent high osmolal contrast-induced acute kidney injury? A randomized controlled trial.

BackgroundN-acetylcysteine (NAC) or sodium bicarbonate (NaHCO3), singly or combined, inconsistently prevent patients exposed to radiographic contrast media from developing contrast-induced acute kidney injury (CI-AKI).ObjectiveWe asked whether intravenous isotonic saline and either NaHCO3 in 5% dextrose or else a high dose of NAC in 5% dextrose prevent CI-AKI in outpatients exposed to high-osmolal iodinated contrast medium more than does saline alone.MethodsThis completed prospective, parallel, superiority, open-label, controlled, computer-randomized, single-center, Brazilian trial (NCT01612013) hydrated 500 adult outpatients (214 at high risk of developing CI-AKI) exposed to ioxitalamate during elective coronary angiography and ventriculography. From 1 hour before through 6 hours after exposure, 126 patients (group 1) received a high dose of NAC and saline, 125 (group 2) received NaHCO3 and saline, 124 (group 3) received both treatments, and 125 (group 4) received only saline.ResultsGroups were similar with respect to age, gender, weight, pre-existing renal dysfunction, hypertension, medication, and baseline serum creatinine and serum cystatin C, but diabetes mellitus was significantly less prevalent in group 1. CI-AKI incidence 72 hours after exposure to contrast medium was 51.4% (257/500), measured as serum creatinine > (baseline+0.3 mg/dL) and/or serum cystatin C > (1.1· baseline), and 7.6% (38/500), measured as both serum creatinine and serum cystatin C > (baseline+0.3 mg/dL) or > (1.25 · baseline). CI-AKI incidence measured less sensitively was similar among groups. Measured more sensitively, incidence in group 1 was significantly (p<0.05) lower than in groups 2 and 3 but not group 4; adjustment for confounding by infused volume equalized incidence in groups 1 and 3.Conclusion:We found no evidence that intravenous isotonic saline and either NaHCO3 or else a high dose of NAC prevent CI-AKI in outpatients exposed to high osmolal iodinated contrast medium more than does saline alone.Trial Registration ClinicalTrials.gov NCT01612013.

Effects of radiographic contrast media on the micromorphology of the junctional complex of erythrocytes visualized by immunocytology.

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.

Ultrasound‐guided injection of the median artery in the standing sedated horse

Injection of the median artery of horses leads to better distribution and persistence of mesenchymal stem cells than i.v. regional limb perfusion. Due to technical difficulties, intra-arterial injections thus far have only been performed under general anaesthesia. To assess the feasibility of injection of the median artery in standing sedated horses. Experimental study. Six horses were included in the study. After median and ulnar regional analgesia, radiographic contrast material was injected in the median artery of both front limbs, using a catheter in one limb and a direct needle injection in the other. Ultrasound guidance was used for catheter and needle placement. Radiographs were obtained for confirmation of successful injection. Post procedural ultrasound examination was performed to assess vascular compromise. Catheter placement was successful in all 6 limbs, but in one limb injection was not possible due to arterial spasm. Movement of the limbs after the initial injection resulted in loss of functionality of the catheter in 2 other horses. Direct needle injection was successful on all 6 limbs, with periarterial extravasation observed in 2 limbs. No clinical complications were observed. Injection of the median artery can be performed in standing horses under sedation. Direct needle injection is a more practical technique than catheterisation, as it is easier to perform and less likely to induce arterial spasm. Periarterial extravasation remains a possible limitation of the technique. Intra-arterial injections may be useful for administration of therapeutic agents such as mesenchymal stem cells on standing sedated horses.

Extravasation of Noncytotoxic Drugs

Extravasation is a potential complication associated with intravenous therapy administration. Inadvertent leakage of medications with vesicant properties can cause severe tissue necrosis, which can lead to devastating long-term consequences. Recognizing potential agents is an essential step in mitigating the risk of extravasation. A literature search was carried out using PubMed with the following key words: extravasation, soft tissue injury, phlebitis, and infiltration, from January 1961 through January 2014. The publications were screened manually and reviewed to identify reports for medications that included synonyms of the International Nonproprietary Name, while excluding antineoplastic agents, radiographic contrast material, investigational or nonmarketed drugs, and animal data, to yield 70 articles. Furthermore, reference citations from publications were also reviewed for relevance and yielded 4 articles. We discovered 232 cases of extravasation involving 37 agents (in order of frequency): phenytoin, parenteral nutrition, calcium gluconate, potassium chloride, calcium chloride, dopamine, dextrose solutions, epinephrine, sodium bicarbonate, nafcillin, propofol, norepinephrine, mannitol, arginine, promethazine, vancomycin, tetracycline, dobutamine, vasopressin, sodium thiopental, acyclovir, amphotericin, ampicillin, cloxacillin, gentamicin, metronidazole, oxacillin, penicillin, amiodarone, albumin, furosemide, lipids, lorazepam, immunoglobulin, morphine, and sodium valproate. Potential properties contributing to extravasation include the following: pH, osmolarity, diluent, vasoactive properties, and inactive ingredients. Antidotes and supportive care agents used in the management of these cases of extravasation include hyaluronidase, phentolamine, terbutaline, topical anesthetics (such as lidocaine and prilocaine cream), topical antimicrobials (such as silver sulfadiazine and chlorhexidine), topical debridement agents (collagenase ointment), topical steroids, and topical vasodilators (nitroglycerin). Data on the management of noncytotoxic extravasations is sparse, consisting primarily of case reports and anecdotal evidence. Fortunately, this adverse outcome is preventable and identification of vesicant agents plays a pivotal role. The intent of this review is to provide a reference identifying noncytotoxic vesicants and the management of extravasations associated with specific agents.

Aspectos anátomo-radiográficos e tempo de trânsito gastrintestinal em jacaré tinga Caiman crocodilus crocodilus (Linnaeus, 1758) (Crocodylia, Alligatoridae)

In Brazil, there is increasing interest in the establishment of captive breeding programs for caiman. However, there is a paucity of in-depth studies on the proper care of these reptiles in captivity, particularly regarding optimal food type and frequency of feeding. The purpose of this study was to determine radiographic-anatomical aspects of, and gastrointestinal transit time of Caiman crocodilus crocodilus using contrast radiography. Ten caiman were used in the study, five males and five females, the animals were physically restrained for administration of a radiographic contrast medium, consisting of 10 ml/kg barium sulfate and mineral oil suspension (70%: 30% respectively), via the orogastric tube. Following contrast medium administration, radiographs were taken via dorsoventral projection first at five minutes, then at 6, 24, 30, 48, 54, 72, 80, 96, 104, 120, 130, 144 and 150 hours. This technique allows visualization of contrast medium passage through the GI tract, which enabled determination of gastrointestinal transit time in the spectacled caiman. The average time for contrast medium passage through the digestive tract of this species was 117 ± 29.6 h for females and 86.4 ± 21.5 h for males.

Effect of Radiographic Contrast Media on the Spectrin/Band3-Network of the Membrane Skeleton of Erythrocytes

The membrane of red blood cells consists of a phospholipid bilayer with embedded membrane proteins and is associated on the cytoplasmatic side with a network of proteins, the membrane skeleton. Band3 has an important role as centre of the functional complexes e.g. gas exchange complex and as element of attachment for the membrane skeleton maintaining membrane stability and flexibility. Up to now it is unclear if band3 is involved in the morphology change of red blood cells after contact with radiographic contrast media. The study revealed for the first time that Iopromide induced markedly more severe alterations of the membrane skeleton compared to Iodixanol whose effects were similar to erythrocytes suspended in autologous plasma. A remarkable clustering of band3 was found associated with an accumulation of band3 in spicules and also a sequestration of band3 to the extracellular space. This was evidently accompanied by a gross reduction of functional band3 complexes combined with a dissociation of spectrin from band3 leading to a loss of homogeneity of the spectrin network. It could be demonstrated for the first time that RCM not only induced echinocyte formation but also exocytosis of particles at least coated with band3.

Radiographic contrast media alterate the localization of actin/band4.9 in the membrane cytoskeleton of human erythrocytes.

Different radiographic contrast media (RCM) were shown to induce morphological changes of blood cells (e.g. erythrocytes or thrombocytes) and endothelial cells. The echinocytic shape change of erythrocytes, particularly, affords alterations of the membrane cytoskeleton. The cytoskeleton plays a crucial role for the shape and deformability of the red blood cell. Disruption of the interaction between components of the red blood cell membrane cytoskeleton may cause a loss of structural and functional integrity of the membrane. In this study band4.9 and actin as components of the cytoskeletal junctional complex were examined in human erythrocytes after suspension in autologous plasma or in plasma RCM mixtures (30% v/v Iodixanol-320 or Iopromide-370) followed by a successive double staining with TRITC-/FITC-coupled monoclonal antibodies. After adding Iopromide-370 to the plasma in practically none of the cells the rounded conformation of the membrane cytoskeleton - as it appeared in cells suspended in autologous plasma - was found. In addition, Iopromide-370 induced thin lines and coarse knob-like structures of band4.9 at the cell periphery while most cell centers were devoid of band4.9, and a box-like arrangement of bands of band4.9. A dissociation between colours red (actin) and green (band4.9) occurred as well. In contrast, erythrocytes suspended in a plasma/Iodixanol-320 mixture showed a membrane cytoskeleton comparable to cells suspended in autologous plasma, Similar results were found with respect to the distribution of actin. This study revealed for the first time RCM-dependent differences in band4.9 activities as possible pathophysiological mechanism for the chemotoxicity of radiographic contrast media.

Acute kidney injury by radiographic contrast media: pathogenesis and prevention.

It is well known that iodinated radiographic contrast media may cause kidney dysfunction, particularly in patients with preexisting renal impairment associated with diabetes. This dysfunction, when severe, will cause acute renal failure (ARF). We may define contrast-induced Acute Kidney Injury (AKI) as ARF occurring within 24–72 hrs after the intravascular injection of iodinated radiographic contrast media that cannot be attributed to other causes. The mechanisms underlying contrast media nephrotoxicity have not been fully elucidated and may be due to several factors, including renal ischaemia, particularly in the renal medulla, the formation of reactive oxygen species (ROS), reduction of nitric oxide (NO) production, and tubular epithelial and vascular endothelial injury. However, contrast-induced AKI can be prevented, but in order to do so, we need to know the risk factors. We have reviewed the risk factors for contrast-induced AKI and measures for its prevention, providing a long list of references enabling readers to deeply evaluate them both.