Allotype-associated differences in concentrations of human IgA2

A prospective clinical trial comparing adverse postmyelographic effects and myelographic quality of metrizamide and iohexol was conducted. Using a predetermined, randomized assignment, 24 horses exhibiting neurologic signs were administered either metrizamide (180 mgl/ml) or iohexol (180 mgl/ml) via cerebellomedullary puncture. Each horse was evaluated postmyelographically for adverse effects. Myelographic quality was assessed by a numerical scoring method. Adverse effects were observed more frequently with metrizamide (21) compared with iohexol (6) myelography (p < 0.05). Seizures, intensification of preexisting neurologic signs and prolonged anesthetic recovery were the most common complications after myelography. There was no difference in myelographic quality (p > 0.05). We conclude that iohexol is safer than metrizamide for equine myelography and that quality myelograms can be obtained with either contrast medium.     

Topoisomerase I inhibitor with potential radiosensitizing effect

The principal aim of this study was to evaluate, on biochemical grounds, whether injection of a low-osmolar nonionic contrast medium (iohexol) can induce a prothrombotic state and/or a change in fibrinolysis. Fifteen patients were submitted to urographic examination and the assays listed below were performed: before the injection (T0), 1 h after (T1), and 24 h after (T24) the injection of the contrast medium. The following assays were performed: fibrinopeptide A (FPA), prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT) and D dimer (D-D). The assays were carried out on 6 of the patients to whom a saline infusion was administered. Only a mild statistically significant increase was found in FPA levels at 1 h after injection of the contrast medium (mean and CI 95%: T0 4.4, 3.7-5.5; T1 6.0, 4.9-9.1; p = 0.003). F1+2, TAT and D-D did not show any significant change after the injection. These findings show that after injection of iohexol, only a mild, though statistically significant, increase in FPA levels was observed as an expression of increased thrombin activity. In the absence of any significant increases in TAT, F 1+2 and D-D, we have no evidence of a prethrombotic state.     

Metrizamide cisternography with hypocycloidal tomography: preliminary results

Metrizamide (Amipaque), a nonionic water soluble contrast agent, has been shown to be safe and efficacious for lumbar myelography. Clinical trials of cervical, thoracic, and even intracranial examinations have produced good results. Despite an inherent neurotoxicity, significant complications have been quite rare, and patient tolerance in general is remarkably good. Preliminary results of metrizamide cisternograms using hypocycloidal tomography are presented to illustrate the anatomic detail which can be demonstrated using this technique.     

Acute hydrocephalus after iotrolan lumbar myelography

A 33-year-old woman with cryoglobulinaemia developed acute hydrocephalus 20 h after lumbar myelography using the water-soluble contrast medium iotrolan. After a ventricular drainage, she was free of symptoms and the hydrocephalus resolved. The development of acute hydrocephalus after myelography has not been reported previously.     

Evaluation of contrast media for bronchography

BACKGROUND: Bronchography is occasionally needed for the evaluation and management of some congenital pulmonary anomalies as well as some acquired diseases, usually of the tracheo- bronchial tree. There is currently no effective, approved contrast agent for this imaging techniq ue. OBJECTIVE: We evaluated five agents (barium sulfate, iohexol, propyliodone oily, propyliodone aqueous, and perflubron) in terms of image quality, histologic changes, and effects on hemodynamics, blood gases, and standard laboratory tests in New Zealand White rabbits. MATERIALS AND METHODS: Animals were anesthetized and intubated. Each contrast agent (0.25 ml/kg) was administered intratracheally. Three animals in each group had intravenous lines placed for blood sampling and blood pressure monitoring and were sacrificed at 1 h. An additional three animals for each agent were sacrificed at 24 h and 1 week after imaging. Blood samples were taken immediately before contrast instillation and at 1 h postbronchography. Fluoroscopic images were recorded on standard VHS video tape and evaluated in blind fashion. Segments of lung tissue and bronchi were obtained for histologic examination. RESULTS: Necrosis and/or inflammatory infiltrates were noted in 78 % of the bronchograms performed with propyliodone aqueous, 67 % with propyliodone oily, 55 % with perflubron, and 33 % with iohexol 120, 240 and 350. No histologic damage was observed with barium. The propyliodones gave the best-quality imaging results and the most histologic changes. Iohexol, in any concentration, gave the least acceptable images and a moderate number of histologic changes. Barium sulfate demonstrated acceptable images with virtually no histologic changes. CONCLUSION: From the histologic and imaging results, barium is the best available contrast material for bronchography.     

Molecular cloning and functional expression of a recombinant 72.5 kDa fragment of the 110 kDa regulatory subunit of smooth muscle protein phosphatase 1M

RATIONALE AND OBJECTIVES: We compared adverse reactions and image quality for hysterosalpingography (HSG) performed with ionic (diatrizoate meglumine combined with iodipamide meglumine [DM + IM]) and nonionic (iohexol) contrast media. METHODS: We performed a study of 95 patients who had HSG and were randomly selected to receive DM + IM or iohexol. Patients reported episodes of abdominal pain and other adverse reactions immediately and 24 hr after the procedure and categorized severity of symptoms on a subjective scale. Two radiologists evaluated image quality for diagnosis. RESULTS: Prevalence of abdominal pain and other reactions both immediately and 24 hr after HSG was lower in patients who received iohexol than in patients who received DM + IM. Moderate or severe abdominal pain was significantly lower in the iohexol group than in the DM + IM group (p < .05). Visualization of the uterine cavity and ampullary rugae was judged excellent with both contrast media (87% with iohexol and 92% with DM + IM). CONCLUSION: Iohexol and DM + IM are excellent contrast media for use during HSG; iohexol 300 may cause fewer episodes of more severe and prolonged abdominal pain.     

Magnetic resonance myelography (MRM) as a spinal examination technique

PURPOSE: Conventional myelography involves side effects and complications due to puncture of CSF space and injection of contrast medium. On the other hand, MR-myelography (MRM) is a new noninvasive method requiring neither puncture nor contrast medium and causing no side effects. The diagnostic value and accuracy of MRM was evaluated in comparison with conventional myelography. MATERIALS AND METHODS: In this prospective comparative study, 41 patients (17 male, 24 female, mean age 42 years) with radicular symptoms underwent conventional lumbar myelography and were also submitted to MRM. Evaluation was performed in a blind manner by two independent examiners. RESULTS: The specificity and sensitivity of the methods are identical. MRM shows 35 cases of thecal indentation with amputation of a nerve root sheath and 6 cases of spinal stenosis. The results of conventional myelography and MRM were surgically confirmed in 38 patients. CONCLUSIONS: Both methods have the same diagnostic accuracy, but MRM requires neither puncture nor contrast medium nor x-rays.     

Local and systemic effects of water-soluble contrast media and barium in rats with chronic small bowel obstruction

RATIONALE AND OBJECTIVES: The local effects on the small intestine and systemic changes produced by different contrast media in small bowel obstruction, with time courses of 4 days, were evaluated. MATERIALS AND METHODS: Four groups, each with 10 normal rats and another four groups (also each with 10 rats) that had ligation of the terminal ileum (obstructed rats) for 4 days were given 3 mL of barium, meglumine sodium diatrizoate, iohexol, or saline (control animals). Radiographs were taken immediately, 1 and 4 hours after administration of contrast media. Immediately before sacrifice, blood samples were taken to determine the hematocrit (Hct), hemoglobin (Hb), white blood cell count (WBC), red blood cell count (RBC), and serum sodium, and potassium and chloride concentrations. Specimens of small bowel were taken for histologic and morphometric analysis. RESULTS: In obstructed rats, the image quality with iohexol improved on final radiographs despite being diluted in the great intestinal contents. There was an improvement in the serum electrolyte concentrations in the obstructed animals that were given any one of the contrast media, the best improvement being in the iohexol groups. A shortening of the length of epithelial cells when any one of the contrast media was administered was observed, as was an increase in the lymphatic space area in the diatrizoate group in normal rats. In the bowel proximal to the obstruction, the lymphatic space area was increased in the diatrizoate group and the size of the epithelial cells was higher in the diatrizoate and iohexol groups compared to the barium and saline groups. CONCLUSION: Our results suggest that iohexol offers good radiologic efficacy and excellent systemic and local tolerance in small bowel obstruction.     

Hepatic imaging with iodinated nanoparticles: a comparison with iohexol in rabbits

RATIONALE AND OBJECTIVES: We evaluated the efficacy of a particulate computed tomography (CT) contrast agent in an animal model of focal liver disease. METHODS: Ethyl ester of diatrizoic acid (EEDA) is an iodinated (89 mg I/ml) nanoparticulate (200 nm) contrast agent intended for intravenous use that is currently undergoing preclinical testing in our laboratory. Focal liver abscesses were created in 11 New Zealand White rabbits. Iohexol and EEDA were administered to each animal on different days. CT scanning was performed at intervals following contrast agent administration. Liver and abscess enhancement were measured and compared. Dynamic imaging experiments in normal animals were also performed using both agents. RESULTS: EEDA resulted in significantly greater enhancement of the liver and liver-to-abscess contrast than did iohexol at all time points beyond 5 min at approximately 25% of the total iodine load. During dynamic imaging, liver and aortic enhancement were greater with EEDA than with iohexol, except during a 20- to 40-sec period immediately following contrast agent administration. CONCLUSION: EEDA is superior to iohexol for imaging liver abscesses. Our results suggest that liver-directed agents such as EEDA may prove to be more efficacious than currently available extracellular agents designed for liver CT scanning.     

Comparison between urinary pyridinium cross-links and hydroxylysine glycosides in monitoring the effects of ovariectomy and 17 beta-estradiol replacement in aged rats

This study was undertaken to assess the sensitivity of hydroxylysylpyridinoline (HP), lysylpyridinoline (LP), galactosylhydroxylysine (GHyl) and glucosylgalactosylhydroxylysine (GGHyl) to monitor bone response to estrogen deficiency and replacement by comparing their excretory patterns in ovariectomized aged (11-14 months old) rats. The ovariectomized (OVX) rats were randomized into two groups: (1) OVX plus vehicle; (2) OVX plus 17 beta-estradiol (17-beta E, 10 micrograms/kg, s.c., 4 days/week). Treatment with 17-beta E started immediately after OVX and continued for 60 days. The collagen catabolites were measured in urine for 1 month before OVX and thereafter for 60 days. In temporal coincidence with urine collection, bone area and bone mineral density (BMD) of lumbar vertebrae, femoral diaphysis and distal metaphysis were measured by dual-energy X-ray absorptiometry. In the untreated rats, BMD of the femoral metaphysis and lumbar vertebrae decreased significantly and the urinary excretion of LP, HP, GHyl and GGHyl increased with different patterns. In the treated rats, 17-beta E replacement prevented the increment in LP excretion, partially prevented the increase in HP excretion, but had no effect on the excretion of GHyl and GGHyl. In conclusion pyridinolines and glycosides have different sensitivities to the bone response to OVX. Glycoside excretion after OVX also reflects metabolic processes not strictly related to bone loss and, in contrast with LP, is not sensitive to estrogen replacement.     

Aspirin and fraxiparine in the prevention of laser induced thrombosis in the presence of iodinated contrast media

The purpose of this study was to investigate the thromboembolic properties of ionic and nonionic contrast media in rats pretreated with aspirin and/or fraxiparine using an experimental model of laser induced thrombosis in the mesenteric microvessels of 17 groups of five male Wistar rats each. Two ionic (ioxaglate and diatrizoate) and two nonionic contrast media (iopamidol and iohexol), alone or associated with antithrombotic drugs (aspirin and/or fraxiparine) were studied. To evaluate the effects of these substances in this model, the number of laser beams needed to induce platelet thrombus formation, the number of emboli detached from the thrombus and the duration of embolization were quantified. Platelet aggregation induced by ADP, induced hemorrhagic time (IHT) and haemoglobin loss level were also determined. Both contrast media injected at 3 ml/kg caused a significant increase in the number of emboli and the duration of embolization (p<0.05). Pretreatment with aspirin and/or fraxiparine in the presence of ionic contrast media showed antithrombotic activities equal to those obtained when they were tested alone (p<0.05), while in the presence of nonionic contrast media, these drugs only neutralised the prothrombotic effects. There were no differences with the NaCl treated group (p>0.05). The ionic contrast media, and to a lesser extent the nonionic contrast medium: iohexol, inhibited platelet aggregation, while iopamidol behaved as an activator. The antithrombotic drugs tested in this study prevent the prothrombotic activities of contrast media therefore suggesting their use before radiographic procedures.     

Quantitative assessment of platelet function and clot structure in patients with severe coronary artery disease

RATIONALE AND OBJECTIVES: Although systemic absorption of enterically administered iohexol and its excretion in urine has been previously documented in rats with ischemic bowel, a practical and sensitive method of detecting urinary iohexol has not been available. We proposed to detect the presence of iohexol in the urine of rats with normal and ischemic bowel by use of a computed tomography (CT) number increase in the bladder with the use of CT. METHODS: Anesthetized rats (250 g) underwent either sham laparotomy (n = 6), ligation of two vascular arcades to the proximal jejunum (n = 5), ligation of six vascular arcades to the proximal jejunum (n = 6), or ligation of the superior mesenteric artery (n = 6). Rats were hydrated with saline (3.2 ml/hr intravenously). Each received a 3-ml enteric bolus of isotonic iohexol. Serial CT scans and plain film radiographs of the bladder were performed at 2, 4, and 6 hr to detect systemic absorption of contrast from the gut. Urine iohexol concentrations were measured by capillary electrophoresis. CT number and iohexol concentration were compared with evidence from plain film radiographs of bladder opacification. Intestinal ischemia was graded histologically. RESULTS: Histologic evidence of ischemia was present in all six-arcade and five of six superior mesenteric artery (SMA)-ligated animals. No animals in the control or two-arcade group showed evidence of bowel ischemia. Statistically significant increases (P < 0.05) in bladder density were demonstrated in the six-arcade and SMA-ligated groups. No statistical difference was noted between the two-arcade ligation and control groups. CONCLUSIONS: Experimental intestinal ischemia was reliably detected by bladder opacification after administration of enteric contrast. CT detection of systemic absorption of enteric iohexol was more sensitive than plain film radiographs and may be useful in the diagnosis of intestinal ischemia, although it may not be specific for ischemia.     

A central nerve conduction study in hypothyroidism: before and after thyroxine replacement

Employing a Nicolet CA 100 machine, 20 patients of primary hypothyroidism were selected for electrophysiological studies, including somato-sensory evoked potential (SSEP), brainstem auditory evoked potential (BAEP), and visual evoked potential (VEP), to assess the central nerve conduction before and after administration of the thyroid hormone. Before thyroxine replacement therapy, the latencies of N9, N13, and N20 in SSEP showed significant delay, while the central conduction time (CCT) merely had a tendency of prolongation. In BAEP, the peak and interpeak latencies delayed significantly. Additionally, the latency and amplitude of VEP also had significant difference between patients and controls. After thyroxine replacement, the SSEP, BAEP, and VEP studies revealed significant improvement, in correlation with clinical amelioration. In conclusion, the central nerve conduction would be affected in primary hypothyroidism and the improvement was usually the case, reflecting the clinical recovery after appropriate treatment. The electrophysiological study provides an objective method for monitoring the function of central nervous system in hypothyroidism before and after thyroxine treatment.     

Sustained transmission of mumps in a highly vaccinated population: assessment of primary vaccine failure and waning vaccine-induced immunity

Electrolyte addition to nonionic contrast media has been suggested to further reduce the incidence of ventricular fibrillation during coronary arteriography. The present study was designed to investigate the effects of adding 30 mM NaCl, 0.9 mM KCl, 0.15 mM CaCl2 and 0.1 mM MgCl2 to iohexol on cardiac electrophysiology and hemodynamics (iohexol+electrolytes = IPE). Contrast media were injected into the left main coronary artery in 9 open-chest, anesthetized dogs before and after induction of acute ischemic heart failure. IPE increased left ventricular inotropy (LV dP/dtmax) with no initial decrease, even during heart failure. During heart failure IPE induced the same hemodynamic effects as iohexol without electrolyte addition. IPE slightly lengthened epicardial monophasic action potential duration before heart failure. We conclude that IPE appears to be well tolerated hemodynamically. The electrophysiologic differences between IPE and iohexol are small when the injection time is not longer than 5 s.     

Side reaction after lumbar myelography with dimer-x (author's transl)

The existence of several very impressive spinal paroxysms after lumbar myelography with Dimer-X1 caused us to make a retrospective investigation of 327 patients with 355 myelographies. In 7.1% of the investigations we have found partly heavy, but mostly reversible neurological complications. The latter cannot be classified, contrary to prevailing statements, in spinal, meningeal or cerebral reactions, since mostly all 3 anatomical structures are being concerned. Corresponding casuistical information are being presented and with their neurological symptomatic discussed. The spinal paroxysms appeared approximately 6 hours after the myelography and lasted over 8-10 hours, in spite of intensive therapeutical efforts. The pathogenesis points to a multifactorial occurrence caused by the coincidence of an increased dosage of the contrast media, too bed rest time, rising of the contrast media in the spinal cord zone and disturbed liquor fluid circulation and contrast media resorption. Pathophysiologically is in connection with spinal cramps an epileptic mechanism probable. Additional spinal reflexive components could be an explanation for the little therapeutical effect of Diacepam (Valium), which is contrary to the statement in the literature. We have seen a better effect in particular cases with Phenothiazine. With strict observance of specific precautionary measures, the Dimer-X seems to be a good media for the presentation of the lumbar subarachnoid space. A further development in this field is desirable.     

A new approach in the treatment of hypotension in human septic shock by NG-monomethyl-L-arginine, an inhibitor of the nitric oxide synthetase

Between 1987 and 1991, 33 patients with spinal stenosis of the lumbar spine were treated by decompression (33 patients) and posterior fusion (30 patients). Indication for decompression was based on case history and lumbar myelography with flexion/extension views. At follow-up 1-5.5 years later, 28 patients were happy with the results of the treatment and would be willing to be operated on again in a similar situation. Two other patients also presented objectively good results, but were dissatisfied for reasons not related to the operation. Our study shows that myelography and case history are adequate investigations for determination of the level of pathology and for making a decision about operative decompression in spinal stenosis of the lumbar spine. CT or MRI are only needed if the symptoms of the patient are not explained by the myelogram. Although MRI is advocated as the investigation of first choice for lumbar spinal stenosis, we still prefer the myelography, which is easier to interpret during the operation. Our study also shows that operative treatment of spinal stenosis is very rewarding, since 9 out of 10 patients will have good results. We usually combine decompression and fusion. Decompression alone is only performed in patients without any back pain and with stable motion segments after adequate decompression.     

Signal averaged electrocardiography (SAECG) in patients on hemodialysis

Cardiovascular diseases are the major cause of mortality in patients on hemodialysis (HD). Recently, signal averaged electrocardiography (SAECG) has been developed to detect ventricular late potentials (LP) noninvasively from the body surface for identifying patients at sudden death or ventricular tachycardia. We performed SAECG in 42 patients before and after HD. As a result, postdialysis total filtered QRS duration (FQRS) was significantly increased compared with predialysis FQRS. Postdialysis duration of low amplitude signal under 40 microV in the latter part of QRS (LAS40) tended to increase compared with predialysis LAS40. Before HD, there were no patients with LP and only one patient (2.4%) with abnormal SAECGs. In contrast, after HD, there were three patients (7.1%) with LP and three more patients (7.1%) with abnormal SAECGs. Furthermore, there was a significant correlation between the changes in LAS40 (delta LAS40) and those in potassium (K) (delta K) during HD. We further examined the relation between LAS40 and the concentration of K, by comparing the correlation coefficient between patients in the high-K group (predialysis K > or = 5.0 mEq/L; 20 patients) and those in the low-K group (predialysis K < 5.0 mEq/L; 22 patients). In the low-K group, there was no significant correlation between delta LAS40 and delta K. However, in the high-K group, there was a significant correlation between delta LAS40 and delta K. In conclusion, SAECG indices worsened during HD, and an insufficient decrement of serum potassium by HD is suggested to have been an arrhythmogenic factor in the high-K group.     

Improved technique for cervical metrizamide myelography

Introduction of metrizamide into the lumbar subarachnoid space with the patient in a prone 15-20 degree head-down position improves delivery of contrast material for cervical myelography. Excellent visualization of the spinal cord and nerve roots has resulted using this technique.     

Alteration of memory in the reduction of children's distress during repeated aversive medical procedures.

The present study sought to reduce children's distress during aversive medical procedures using a brief cost-effective intervention aimed at reframing memory. Fifty children diagnosed with leukemia (25 treatment, 25 attention control, aged 3–18) were observed as they underwent 3 consecutive lumbar punctures (LPs; baseline, postintervention, and follow-up). Self-report, physiological, and observable distress measures were collected before and after each LP. At posttreatment, children in the intervention group showed reductions in anticipatory physiological and self-report ratings relative to the control group. At follow-up, these effects generalized to reductions in procedural distress. These results suggest that (a) a simple memory-based intervention is efficacious at reducing children's distress and (b) benefits from this intervention are maintained over 1 week even without continued intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of a national impregnated bed net programme on the outcome of pregnancy in primigravidae in The Gambia

The effect of the non-ionic contrast medium iohexol (Omnipaque) on renal function was investigated in diabetic patients with signs of peripheral ischaemia. Forty-six patients, 70 +/- 11 years (mean +/- SD) old, age at diabetes diagnosis 53 +/- 17 years, and with varying degrees of diabetic nephropathy were studied before 1, 2, and 30 days after aortobifemoral arteriography. Serum creatinine, creatinine clearance, urinary excretion of immunoglobulin G, albumin collagen IV (NC1), kappa and lambda chains, alpha-1 microglobulin and Tamm-Horsfall protein were evaluated. Within 1 month before and 30 days after arteriography, the glomerular filtration rate was measured by clearance of iohexol. The acute effect of the radiocontrast medium was an increase in the serum creatinine level in 41 (89%) patients, with a more than 25% increase in 12 (26%) patients. The excretion rates of immunoglobulin G and albumin decreased, whereas the proximal and distal tubular function and the excretion of collagen IV did not change. The increment in serum creatinine was associated with the preangiographic renal function (p < 0.05), a history of heart failure (p < 0.01), but not with age, duration and type of diabetes, gender, systolic or diastolic blood pressure, glycated haemoglobin (HbAlc) or blood glucose levels. The increase of serum creatinine was associated with a pre-existing proximal tubular dysfunction and a worsening of distal tubular function. No changes in the parameters measured persisted 30 days after angiography. In summary, a transient increment in serum creatinine level after arteriography occurred in 89% of diabetic patients. It was associated with the preangiographic renal function, a history of heart failure and signs of preexisting proximal tubular dysfunction and worsening of distal tubular function. However, these changes were reversible.