Fraga de Suarez, A.; Mitta, A.E.A.; Parera, V.E.
The preparation of pyridoxylideneglutamate 99 sup(m)Tc is described ITLC (S.G.) is suggested as a test method, the compound was assayed in rabbits and the stability of a non liofilized kit was determined. (author) [es
Matolo, N.M.; Stadalnik, R.C.; Wolfman, E.F. Jr.
Technetium 99m-pyridoxylideneglutamate (99mTc-PG) administered intravenously is excreted by hepatocytes into the bile canaliculi and enters the gallbladder through the cystic duct and consequently, can be used for scanning the hepatobiliary ductal system. A total of 166 patients representing 27 normal subjects, 84 patients referred for investigation for pain in the upper right quadrant of the abdomen and 55 jaundiced patients were evaluated with 99mTc-PG. In normal human volunteers, the agent reached the liver in five minutes, and the common bile duct, gallbladder, and duodenum within 15 minutes. Satisfactory images of the hepatobiliary tract were obtained using small dosages of 99mTc-PG. The gallbladder was not visualized when the cystic duct was occluded. In the presence of acute cholecystitis, cystic duct obstruction, or in chronic cholecystitis where other roentgenographic studies showed a nonfunctioning gallbladder, there was no concentration of 99mTc-PG in the gallbladder. In partial common bile duct obstruction, distended common bile duct was visualized along with delay in transit of radioactivity into the duodenum. Complete common bile duct obstruction was associated with no radioactivity in either the biliary or the gastrointestinal tracts up to 24 hours after injection. Hepatocellular disease was characterized by delayed liver clearance and delayed visualization of biliary and gastrointestinal tracts. 99mTc-PG scanning proved capable of differentiating betweenhepatocellular disease and extrahepatic biliary tract obstruction
Lubin, E.; Rachima, M.; Oren, V.; Kozenitzky, I.; Rechnic, Y.; Wininger, J.; Trumper, J.
Sixty patients, 56 of them jaundiced, were examined after the injection of 99 Tc-pyridoxylideneglutamate, a substance which is rapidly concentrated by normal hepatocytes and excreted into the biliary tract, appearing in the gall-bladder after 10-15 min and in the gastrointestinal (GI) tract at 30 min. On the basis of the time of appearance in the GI, four groups of patients were delineated: I - 15 patients with a normal pattern, with visualization of the GI at 30 min; II - 10 patients with a slight delay in passage, with appearance in the GI after 30-180 min; III - 21 patients showing a very slow excretion visualized only at 24 hours (17 of these had parenchymatous disease of the liver, 2 choledocholithiasis and 2 pancreatic tumours causing partial obstruction); IV - 14 patients with no visualization of the GI, 6 of whom proved to be cases of medical jaundice and 8 surgical cases. When the 20 min/5 min plasma activity ratio was calculated and expressed as percentage retention, values higher than 76 were found only in 4 patients with parenchymatous jaundice. In view of these results, it was concluded that this method does not give a sufficiently reliable differentiation between extrahepatic biliary obstruction and severe parenchymatous disease. (author)
Baker, R.J.; Marion, M.A.
Technetium-99m pyridoxylideneglutamate biliary scans were performed in 19 normal subjects in both the fasted and nonfasted state. The effect of eating was to reduce visualization of the gallbladder from 100% (fasted) to 47% (nonfasted). The common bile duct was seen in 84% on both occasions but intrahepatic and cystic ducts were seen less frequently in the nonfasted group. Preparation of patients by fasting is essential if information concerning gallbladder function is sought
Jansholt, A.L.; Krohn, K.A.; Stadalnik, R.C.; Matolo, N.M.; DeNardo, G.L.
Various Tc-99m-labeled compounds have been suggested as replacements for [I-131] rose bengal for imaging of the hepatobiliary system. Among such compounds are Schiff's bases, which are tin-free Tc-chelates easily prepared by 30-min autoclaving of an equimolar mixture of pyridoxal and an amino acid at pH 8.5. We have compared the properties of several Schiff's bases, including Tc-99m pyridoxylideneglutamate (Tc-PyG) with [I-131] rose bengal. Under conditions described, Tc-PyG can be prepared free of Tc-pyridoxal and with 4 - radiochemical impurity. Blood clearance and biliary excretion were studied in three animal models and in normal human volunteers. In all animal models, Tc-PyG initially cleared from the blood more rapidly than rose bengal, but a significant amount of Tc-PyG was excreted in the urine, this in contrast to [I-131] rose bengal which was almost completely excreted through the biliary system. Species differences were observed in the degree of urinary versus biliary clearance of Tc-PyG, with significantly greater urinary excretion in dogs than in monkeys and rabbits. Replacing glutamate with other amino acids did not significantly increase the blood clearance rate or decrease urinary excretion, so that Tc-PyG appears to be at least as good as any of the others studied. Tc-PyG was only 20% bound to plasma proteins, and electrophoretic and chromatographic studies did not reveal any in vivo changes of Tc-PyG before excretion in urine or bile
Williams, J.A.; Baker, R.J.; Walsh, J.F.; Marion, M.A.
The diagnostic accuracy of biliary scanning using /sup 99m/Tc-pyridoxylideneglutamate has been determined in a series of 51 surgically jaundiced patients. This noninvasive technique was found to be safe, reliable and universally applicable in all instances of jaundice, regardless of the serum bilirubin value or prothrombin time. The results were found to compare favorably with those of other investigative procedures. It is suggested that the /sup 99m/Tc-pyridoxylideneglutamate biliary scan is most advantageously carried out after clinical assessment and full biochemical evaluation of the patient. The scan result will indicate the next logical step in the management of the patient whether it be endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography, biopsy of the liver or laparotomy
Verdegaal, W P
The use of hepatobiliary scintigraphy is discussed on the basis of personal observations with sup(99m)Tc-pyridoxylideneglutamate (sup(99m)Tc-PG). Hepatobiliary scintigraphy appears to be a useful tool in differentiating the causes of jaundice. Its value as a test for biliary reflux to the stomach and as a method to evaluate the function of intestinal and bilidigestive anastomoses needs further investigation.
Baker, R.J.; Bellen, J.C.
The use and chemical preparation of sup(99m)Tc-pyridoxal or any amino acid derivitive of pyridoxal labelled with technetium-99m or other radionuclide is described. These compounds include sup(99m)Tc-pyridoxylidenemethioninate, sup(99m)Tc-pyridoxylidenetyrosinate and in particular sup(99m)Tc-pyridoxylideneglutamate. The substances specified above all show sufficient accumulation in the gall bladder to enable this organ to be visualised by scintiscanning. (author)