Liver Glutathione Contents in Patients with Gastric Adenocarinomas

Many antineoplastic agents alter the reduced glutathione (GSH) status of liver and tumor tissue by inhibiting cellular GSH-linked enzymes. Thus, intracellular GSH plays an important role in a wide variety of antineoplastic interventions regarding therapeutic efficacy and toxicity. Mean GSH values were 0.791 ± 0.072 mg/m wet weight (ww) and 0.719 ± 0.047 mg/g ww in gastric cancer tissue and nontumorous glandular mucosa, respectively. Whereas, the average GSH level of normal gastric mucosa was 1.709 ± 0.135 mg/g, the mean GSH level of normal liver biopsies was 2.378 ± 0.260 mg/g. The GSH values of normal liver tissue were higher than the hepatocellular GSH concentrations of patients with gastric adenocarcinoma and of another group of tumor-bearing patients who had received chemotherapy preoperatively. These results suggest that the GSH levels of tumor and liver may influence the efficacy and/or toxicity of chemotherapeutic agents.

Storage Levels of Ddt Metabolites in Mouse Tissues following Long Term Exposure to Technical DDT

The storage levels of DDT and its metabolites, following the long term administration of technical DDT at the dose levels of 2, 20, 50 and 250 ppm to mice, were evaluated in the fat tissue, liver, kidney, brain and reproductive organs. In addition, storage levels were evaluated in foetuses and newborns of DDT-treated mothers. Apart from op'-DDT, there was a direct relationship between the concentration of each metabolite in each organ and the dose to which the animal was exposed. The highest concentration of DDT and metabolites was found in the fat tissue followed by reproductive organs, liver and kidney together, and lastly brain. The most prevalent metabolite was pp'-DDT, except in the liver, where pp'-DDD showed the highest concentration. Pregnant females had lower concentrations of all metabolites than non-pregnant females. The concentration of residues in samples of total foetal litters was directly related to the concentration of DDT fed to the mother. There was a strong negative correlation between the concentration of pp'-DDT and that of pp'-DDD in the foetuses and the placentas of the same litter. A significant increase in whole body DDT concentration was observed shortly after birth.

Effect of Some Selected Anti-Inflammatory Steroids on Elastin Content in Liver of Rats Treated with Carbon Tetrachloride

Hepatic fibrosis was induced in rats by poisoning them with carbon tetrachloride. The influence of anti-inflammatory steroids (hydrocortisone, prednisone, dexamathasone) upon elastin content in liver was investigated in healthy and CCl4 intoxicated rats. An increase of liver elastin content was observed in animals with CCl4-induced hepatic fibrosis Opposite results were obtained in normal rats after treating them with glucocorticosteroids. A decrease of elastin content after steroid treatment was also found in rats with injured liver, as compared to animals receiving CCl4 only. Presumable mechanisms of the results are discussed.

Tissue zinc at autopsy--relation to medication with diuretics

Diuretic treatment has been shown to cause a substantial increase in the urinary output of zinc. However, the serum zinc levels remain normal or even raised. In the present study, tissue zinc was studied in liver, kidney and skeletal muscle tissue from 147 consecutive autopsies. In 90 of the cases heart muscle and aortic tissue were also studied. The zinc values were correlated to previous treatment with diuretics. A lower liver zinc level was observed in the group of patients who had been on diuretic treatment for more than 6 months compared to the group without treatment, the difference being highly significant. The skeletal muscle zinc was also low in the patients who had been on diuretic treatment. With regard to the metabolic functions of zinc, the tissue depletion of this element after diuretic treatment may be of clinical importance.

Identification and characterization of different amyloid fibril proteins in tissue sections

Antisera specific for 4 different classes of amyloid fibril proteins, amyloid protein AA and the immunoglobulin light-chain amyloid proteins AlambdaI, AlambdaIV, and AlambdaV, were used to identify these proteins directly in tissue sections from 25 patients with amyloidosis. The specificity of these reactions was established by blocking experiments with purified amyloid fibril proteins and Bence Jones proteins of known variable subgroups. Protein AA was detected in 17 patients, including all 13 with secondary amyloidosis, 2 with primary amyloidosis and 2 with Waldenström's macroglobulinemia. Immunoglobulin light-chain proteins AlambdaI, AlambdaIV, and AlambdaV were in 3, 1, and 2 patients, respectively, all of whom had primary or myeloma/macroglobulinemia-associated amyloidosis. Antiserum specific for the amyloid-related serum protein SAA reacted with the same tissues as anti-AA and had the same pattern of staining in tissue sections.

Metallothionein: an exceptional metal thiolate protein

Metallothioneins are unusual, low molecular weight proteins of extremely high sulphur and metabl content. They occur in substantial quantity and in multiple variant forms in parenchymatous tissues (liver, kidney, intestines) of vertebrates and certain microorganisms (Neurospora crassa, yeast). They are though to play a central role in the cellular metabolism of metals such as zinc, copper and cadmium. All mammalian forms studied are single chains with 20 cysteinyl residues among a total of 61 amino acid residues and highly characteristic amino acid sequences. Their most conspicuous common features are seven -Cys-X-Cys- sequences where X stands for an alphatic residue other than Cys. Together with additional cysteinyl residues located elsewhere in the chain and brought into juxtaposition by appropriate chain folding, these dithiol sequences are believed to form the basis of the trithiolate chelating structures typical of most of the six or seven metal-binding sites of the mammalian cadium- and/or zinc-containing metallothioneins. The positions of the cysteinyl residues are preserved in evolution: the copper-containing metallothionein from Neurospora crassa, containing only 25 amino acid residues, has a distribution of metal-binding cysteinyl residues identical to that of the N-terminal portion of the mammalian chains. The detailed physiological role of metallothionein remains to be clarified but its biosynthesis is known to be modulated by nutritional and endocrine factors. Recent evidence suggests that metallothionein is a critical determinant in the homeostasis of zinc.

Isolation and characterization of binder IIIA, a new protein which binds corticosteroid anions

A new protein binding corticosteroid metabolites has been purified over 300-fold from liver cytosols of adrenalectomized rats, treated for 45 min in vivo with [1,2-3H]cortisol. Purification was accomplished by column chromatography on Sephadex G-25, DEAE-Sephadex A-50, Sephadex G-75, and hydroxylapatite. The protein has a Stokes radius of 2.27 nm by gel filtration and an apparent sedimentation coefficient of 3.0 S by sucrose gradient centrifugation. The calculated molecular weight is 30,700. The bound steroid was extracted and has been shown by Sephadex LH-20 chromatography to be a monosulfate derivative of cortisol. Using liver cytosol from adrenalectomized rats pretreated in vivo for 45 min with [1,2-3H]cortisol plus 1000-fold excess competing steroid, cortisol derivatives and progesterone were shown to be the most active competitors. Testosterone and 17 beta-estradiol were least active as competitors. The synthetic steroids, dexamethasone and triamcinolone, produced little or no competition. The protein has been named corticosteroid-anion binder IIIA in keeping with its elution position from a DEAE-Sephadex A-50 column, compared to other binding proteins. Binder IIIA has been separated chromatographically from the glutathione S-transferases (including ligandin) and protein z described by Arias [Levi, A.J., Gatmaitan, Z. and Arias, I.M. (1969) J. Clin. Invest. 48, 21856-21866], both of which have been shown to bind anionic metabolites. It has been resolved from the activities of transcortin, cortisone 5 beta-reductase, and 3 alpha-hydroxysteroid dehydrogenase.

Hepatic iron overload: diagnosis and quantification by noninvasive imaging

The diagnostic efficacy of magnetic resonance (MR) and computed tomography (CT) for detection and quantification of hepatic iron was assessed in a series of patients under investigation for clinical or biochemical evidence of hepatic iron overload. Thirty patients underwent MR imaging (SE 30,60/1000 or SE 30,60/2000) at 0.5 Tesla with calculation of hepatic T2 and liver to paraspinous muscle signal intensity ratios. Twenty-nine patients also had measurement of hepatic attenuation on noncontrast CT images. Results of these imaging studies were correlated in all patients with quantitative iron determination from liver biopsy specimens. The best predictor of liver iron among parameters studied was the ratio of the signal intensities of liver and paraspinous muscle (L/M) on a SE 60/1000 sequence. Both MR using L/M ratios and CT were sensitive methods for detection of severe degrees of hepatic iron overload with 100% of patients with hepatic iron on biopsy greater than 600 micrograms/100 mg liver dry weight detected on the basis of L/M less than 0.6 or CT attenuation greater than 70 Hounsfield units (HU). The MR parameter, however, was more specific than CT (100 vs 50%) and showed a higher degree of correlation with quantitated hepatic iron from biopsy. T2 measurements showed poor correlation with hepatic iron, due to difficulty in obtaining precise T2 measurements in vivo when the signal intensity is low. None of the parameters utilized was sensitive for detecting mild or moderate degrees of hepatic iron overload. We conclude that MR and CT are sensitive techniques for noninvasive detection of severe hepatic iron overload, with MR providing greater specificity than CT.(ABSTRACT TRUNCATED AT 250 WORDS)