Biomedical subjects

T P Mulder

Publications and source records attributed to T P Mulder.

7 recordsLinked to original sources

PubMed1992

Metallothionein concentration in the liver of patients with Wilson's disease, primary biliary cirrhosis, and liver metastasis of colorectal cancer.

In patients with primary biliary cirrhosis and Wilson's disease liver copper concentrations become elevated during the evolution of the disorder. The accumulated copper is thought to be detoxified by metallothionein, a protein which binds copper and zinc. In liver metastasis of colorectal cancer, copper and zinc concentrations are usually decreased compared to normal liver tissue, but little is known about the concomitant metallothionein levels. In the present study metallothionein concentrations were determined in archival liver samples from patients with primary biliary cirrhosis and Wilson's disease, and in both normal and malignancy-containing liver samples from patients with metastasis from a colorectal adenocarcinoma. Twenty-seven control liver samples contained 3.98 +/- 1.55 mg metallothionein/g protein. From the 21 liver samples of patients with primary biliary cirrhosis, which had a mean metallothionein concentration of 6.06 +/- 5.03 mg/g protein, 6 were above the highest control level. Liver metallothionein concentrations for the 8 patients with Wilson's disease were significantly elevated (10.98 +/- 6.93 mg/g protein, p < 0.005 vs. controls and p < 0.05 vs. primary biliary cirrhosis). In the 11 liver metastases from colorectal adenocarcinomas metallothionein concentrations (1.17 +/- 0.90 mg/g protein) were significantly (p < 0.005) lower than surrounding normal liver tissue (4.25 +/- 1.75 mg/g protein). We conclude that in primary biliary cirrhosis and Wilson's disease increased liver metallothionein concentrations may detoxify the accumulated copper. Furthermore, liver metastasis of colorectal cancer contains less metallothionein than the surrounding normal liver tissue.

Adenocarcinoma↗

PubMed1991

Decrease in two intestinal copper/zinc containing proteins with antioxidant function in inflammatory bowel disease.

Oxygen derived radicals contribute to tissue injury in inflammatory bowel disease. We measured the content of superoxide dismutase and metallothionein (two endogenous copper and zinc containing proteins involved in radical scavenging) in intestinal resection specimens from 29 patients with Crohn's disease and 12 patients with ulcerative colitis and compared the concentrations with those obtained in the normal mucosa of a control group of 18 patients with colorectal cancer. The superoxide dismutase content was similar in control mucosa and non-inflamed mucosa from patients with inflammatory bowel disease (mean (SEM) 2.13 (0.10) and 2.24 (0.10) mg/g protein, respectively) but was decreased in inflamed mucosa (1.87 (0.08) mg/g protein, p less than 0.005 v non-inflamed mucosa). The metallothionein content was decreased in non-inflamed inflammatory bowel disease mucosa compared with control mucosa (0.23 (0.03) and 0.36 (0.04) mg/g protein, respectively, p less than 0.02) and a further decrease was found in inflamed mucosa (0.17 (0.02) mg/g protein, p less than 0.001 v control mucosa). No differences were found between Crohn's disease and ulcerative colitis and no significant effect of medication or tissue localisation was noted. These findings might indicate a decreased endogenous intestinal protection against oxygen derived radicals in inflammatory bowel disease which could contribute to the pathogenesis of the disease.

Adolescent↗

PubMed1991

Reactive oxygen metabolites and colitis: a disturbed balance between damage and protection. A selective review.

Enhanced local production of reactive oxygen metabolites has been found in association with colitis, both experimentally and in humans. Cellular and biochemical systems involved have been identified, and 5-aminosalicylic acid-containing drugs but, more effectively, specific scavengers have been found to reduce the intestinal inflammatory process. The multitude of reactions in which oxygen metabolites participate provides a new area of research in intestinal inflammation. These basic studies might bring related clinical studies in an era of new anti-inflammatory drugs for inflammatory bowel disease specifically designed to scavenge toxic oxygen metabolites.

Animals↗

PubMed1991

Plasma metallothionein concentration in patients with liver disorders: special emphasis on the relation with primary biliary cirrhosis.

The plasma metallothionein concentration was evaluated in healthy subjects and in patients with several types of liver disorders. Plasma metallothionein concentrations in controls varied between 2.4 and 4.8 ng/ml. Patients with disorders associated with increased liver copper concentrations (i.e., primary biliary cirrhosis and primary sclerosing cholangitis) had significantly (both p less than 0.002) elevated plasma metallothionein concentrations (range = 1.8 to 52.2 ng/ml), and a considerable number of these were above the maximum control level (21 of 41 patients). In contrast, patients with liver disorders not associated with increased liver copper concentrations (alcoholic and cryptogenic cirrhosis, and acute viral and chronic active hepatitis) generally had normal plasma metallothionein concentrations and only a few were above the maximum control level (11 of 64 patients, maximum = 8.8 ng/ml). The metallothionein concentrations in plasma samples from patients in stage I or II primary biliary cirrhosis were within or slightly above the control range, whereas most patients in stage III had elevated levels (p less than 0.002), and almost all patients in stage IV had clearly elevated (p less than 0.0001) concentrations. In primary biliary cirrhosis the plasma metallothionein concentration tended to increase during the evolution of the disorder, and the concentration correlated significantly with the serum total bilirubin concentration. In conclusion, the plasma metallothionein concentration is significantly elevated in patients with primary biliary cirrhosis and in patients with primary sclerosing cholangitis. Although related to the histological stage of primary biliary cirrhosis, the measurement of plasma metallothionein concentrations contributes little to the diagnosis or the evaluation of the severity of these disorders.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

PubMed1990

Isolation, characterization, and determination of human liver (copper/zinc) metallothionein.

A copper-containing protein was purified from the liver of a patient with primary biliary cirrhosis by a combination of gel filtration and anion exchange chromatography. This copper-protein had UV absorption and emission spectra, an amino acid composition, and a molecular mass which were characteristic for metallothionein (MT). From 8 livers (3 control, 1 fetal and 4 primary biliary cirrhosis) MT was extracted with non-reducing buffer and centrifuged, and pellets were re-extracted with a 1% 2-mercaptoethanol-containing buffer. The non-reducing buffer extracted a predominantly copper-containing MT from the livers of patients with primary biliary cirrhosis and a predominantly zinc-containing MT from control livers and the fetal liver. Only from the fetal liver was a copper/zinc containing MT solubilized during the re-extraction with 2-mercaptoethanol-containing buffer. These results indicate that human MT is a unique metalloprotein with age and disease-dependent characteristics.

Amino Acids↗

PubMed1990

Development of a radioimmunoassay for human metallothionein.

We report the development of a radioimmunoassay (RIA) for human metallothionein (MT). The MT was isolated from the liver of a patient with primary biliary cirrhosis and used to raise high titer antibodies in rabbits. The RIA was developed using Bolton-Hunter labeled MT as label and purified MT as standard. The detection limit of the assay was 0.4 ng/ml and concentrations between 0.8 and 100 ng/ml could be routinely measured. Dilutions of plasma samples containing high endogenous MT concentrations and tissue extracts in assay buffer showed parallelism with the standard curve and MT added to plasma could be fully recovered.

Humans↗

PubMed1990

Neoplasia-related changes of two copper (Cu)/zinc (Zn) proteins in the human colon.

Cu/Zn-containing proteins have recently become of interest with regard to their relation with malignant disorders. Cu Zn-superoxide dismutase (Cu/Zn-SOD) was found increased in chemically induced tumors of the large bowel whereas metallothionein (MT), containing Zn and some Cu, was shown important for the response of tumors to chemotherapy. In the present study, we evaluated the Cu/Zn-SOD and MT content of normal human colonic mucosa and colorectal carcinomas, obtained from 20 resection specimens, and of 47 adenomatous polyps. The Cu/Zn-SOD content of polyps and carcinomas was significantly (p less than 0.01) elevated when compared to normal mucosa. In the adenomatous polyps the Cu/Zn-SOD content increased significantly with increasing grade of epithelial cell dysplasia, diameter, and presence of a villous component. In the carcinomas no relation was noticed between the Cu/Zn-SOD content and the Dukes' stage or the grade of differentiation. The MT content was significantly decreased in both adenomatous polyps and carcinomas when compared to that in normal mucosa. The MT content was not related to the grade of epithelial cell dysplasia of the polyps, and to the Dukes' stage or the differentiation of the carcinomas. In conclusion, neoplasia of the colorectum is accompanied by an increase in Cu/Zn-SOD and a decrease in MT. These findings support the association between changes in Cu/Zn proteins and malignancy.

Adenocarcinoma↗