Metrizamide

QH13NO5 3416-24-8) see Metrizamide a-D-glucosamine hydrochloride (QH14CINO5 14131-62-5) see Glucaffletacin glucoscillaren A... 

Siitterlin U, Thies W-G, Haffher H, et al. 1984. Comparative studies on the lysosomal association of monomeric 239Pu and 241Am in rat and Chinese hamster liver Analysis with sucrose, metrizamide, and percoll density gradients of subcellular binding as dependent on time. Radiat Res 98 293-306. 

The first modern hydrophilic nonspecific iodinated CA was diatrizoic acid, which, formulated as a sodium and/or meglumine salt, is still used. This agent was first synthesized in 1953 [1]. Osmolality for this compound, at concentrations compatible with imaging (ie. 300-370 mgl mL" ), is about 5-7 times that of plasma (1500-2100 mOsm kg H2O). Other HOCA such as iothalamate, metrizoate and ioxithalamate, were synthesized and marketed over the next few years. In an attempt to reduce the osmolality of the injected solution and thus reduce pain and haemodynamic disturbances, metrizamide, a compound resulting from the condensation of metrizoic acid and glucosamine, was synthesized. It was the first nonionic CA. 

The aggregation of metrizamide in solution further reduced its osmolality to about 485 mOsm kg at 300 mgl mL [ 1 ]. Unfortunately, this agent could not be sterilized by autoclaving and, consequently, had to be lyophilized and reconstituted extemporaneously. In the mid-1970s, stable nonionic compounds such as iopamidol or iohexol superseded metrizamide. Further improvement was reached by stabilization of the hydrophilic sphere against external disruption, as shown with iobitridol [2]. 

Hypomania Hypomania has been the most common severe psychiatric side effect reported. This has been largely limited to patients in whom disorders characterized by hyperkinetic symptoms coexist with, but are obscured by, depressive affect. Diabetes There is conflicting evidence as to whether MAOIs affect glucose metabolism or potentiate hypoglycemic agents. Consider this if used in diabetics. Epilepsy The effect of MAOIs on the convulsive threshold may vary. Do not use with metrizamide discontinue MAOl 48 hours or more prior to myelography and resume 24 hours postprocedure. 

Drugs that may affect MAOIs include dibenzazepine-related entities, disulfiram, methylphenidate, metrizamide, and sulfonamide. 

In this method, usually a density profile is formed in the ultracentrifugation cell by centrifuging solutions for instance of sucrose or Metrizamide in water or methanol until the equilibrium state between sedimentation and diffusion of the dissolved molecules has been established. Figure 1 shows schematically two of such equilibrium density profiles (dotted lines). 

The cytoplasmic organelles may be separated from each other by differential centrifugation or by density gradient centrifugation using sucrose or one of the commercially available alternatives, e.g. Percoll or Metrizamide. Some alternative approaches are considered by Howell et al. (1989). 

The role of chlorpromazine in facilitating metrizamide-induced convulsions has been confirmed in animal studies... 

Robertson GH, Taveras JM, Tadmor R, et al. Computed tomography in metrizamide cisternography importance of coronal and axial views. J Comput Assist Tomogr 1977 1 241. 

Of 18 German patients undergoing lumbar myelography with metrizamide, six had an organic psychosis, characterized by impaired memory and depression, but it was demonstrable only by psychometric tests and disappeared within 5 days (415). In four of the 18 patients there was hyporeflexia or areflexia and in three there were electro-encephalographic changes there was no correlation between these various types of effect. 

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